U.S. patent application number 11/573489 was filed with the patent office on 2009-09-10 for can container.
This patent application is currently assigned to DAIWA CAN COMPANY. Invention is credited to Wataru Hasegawa, Yoshihiko Matsukawa.
Application Number | 20090223956 11/573489 |
Document ID | / |
Family ID | 35839436 |
Filed Date | 2009-09-10 |
United States Patent
Application |
20090223956 |
Kind Code |
A1 |
Matsukawa; Yoshihiko ; et
al. |
September 10, 2009 |
CAN CONTAINER
Abstract
An easily rupturable portion, which is ruptured when an inner
pressure of a can container is raised extraordinary and the domed
portion is thereby deformed to protrude outwardly of the can
container, is formed on an outer face side of the domed portion and
situated in the close vicinity of an outer circumferential portion
of the domed portion continuing into a seamed portion. For example,
the easily rupturable portion is ruptured to release the contents
of the can container when an inner pressure of a can container is
raised extraordinary by heat or the like to deform the domed
portion of a bottom lid to protrude outwardly within the outer
circumferential portion of the domed portion. Therefore, a gas can
be released without blowing off a portion of the can container.
Inventors: |
Matsukawa; Yoshihiko;
(Kanagawa, JP) ; Hasegawa; Wataru; (Kanagawa,
JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
DAIWA CAN COMPANY
Chuo-ku
JP
|
Family ID: |
35839436 |
Appl. No.: |
11/573489 |
Filed: |
August 8, 2005 |
PCT Filed: |
August 8, 2005 |
PCT NO: |
PCT/JP05/14860 |
371 Date: |
February 9, 2007 |
Current U.S.
Class: |
220/89.2 |
Current CPC
Class: |
F17C 13/123 20130101;
B65D 51/1638 20130101; F17C 1/14 20130101; F17C 2260/042 20130101;
F17C 2260/021 20130101; F17C 2203/0636 20130101; F17C 2201/0104
20130101; F17C 2203/069 20130101; F17C 2203/0617 20130101; F17C
2270/0718 20130101; B65D 83/70 20130101; B65D 83/38 20130101; F17C
2201/058 20130101 |
Class at
Publication: |
220/89.2 |
International
Class: |
B65D 90/36 20060101
B65D090/36 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 10, 2004 |
JP |
2004-233458 |
Claims
1-6. (canceled)
7: A can container which includes an annular ground contacting
portion formed on a lower end of the can container, and a domed
portion whose longitudinal section is arcuate, which protrudes
inward of the can container, and which is connected to an upper end
of an inner circumferential face of the annular ground contacting
portion extending near vertically, wherein: an easily rupturable
portion, which is ruptured when an inner pressure of the can
container is raised extraordinary and the domed portion is thereby
deformed to protrude outward of the can container, is formed on an
outer face side of the domed portion and situated in close vicinity
of an outer circumferential portion of the domed portion continuing
into the annular ground contacting portion.
8: The can container as set forth in claim 7, wherein: the easily
rupturable portion is formed radially inward of the outer
circumferential portion of the domed portion within a predetermined
range.
9: The can container as set forth in claim 7, wherein: the easily
rupturable portion is a score line whose longitudinal section is an
inverted trapezoidal shape formed by a pair of inclined lateral
faces that are tapered from the outer face side of the domed
portion toward the inner face side and a bottom face connecting the
inclined lateral faces.
10: The can container as set forth in claim 8, wherein: the easily
rupturable portion is a score line whose longitudinal section is an
inverted trapezoidal shape formed by a pair of inclined lateral
faces that are tapered from the outer face side of the domed
portion toward the inner face side, ad bottom face connecting the
inclined lateral faces.
11. The can container as set forth in any of claim 7, wherein: a
planar shape of the easily rupturable portion is an approximate
semicircular shape, and end portions thereof are extended
approximately in the radial direction of the can container.
12: The can container as set forth in claim 8, wherein: a planar
shape of the easily rupturable portion is an approximate
semicircular shape, and end portions thereof are extended
approximately in the radial direction of the can container.
13: The can container as set forth in claim 9, wherein: a planar
shape of the easily rupturable portion is an approximate
semicircular shape, and end portions thereof are extended
approximately in the radial direction of the can container.
14: The can container as set forth in claim 10, wherein: a planar
shape of the easily rupturable portion is an approximate
semicircular shape, and end portions thereof are extended
approximately in the radial direction of the can container.
15: The can container as set forth in claim 7, wherein: at least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
16: The can container as set forth in claim 8, wherein: at least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
17: The can container as set forth in claim 9, wherein: a least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
18: The can container as set forth in claim 10, wherein: at least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
19. The can container as set forth in claim 11, wherein: at least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
20: The can container as set forth in claim 12, wherein: at least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
21: The can container as set forth in claim 13, wherein: at least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
22: The can container as set forth in claim 14, wherein: at least a
portion of the easily rupturable portion is situated within a range
of 3 mm from the outer circumferential portion of the domed
portion.
23: The can container as set forth in claim 9, wherein: a width of
a bottom face of the score line is 0.03 mm to 0.1 mm.
24: The can container as set forth in claim 10, wherein: a width of
a bottom face of the score line is 0.3 mm to 0.1 mm.
25: The can container as set forth in claim 13, wherein: a width of
a bottom face of the score line is 0.03 mm to 0.1 mm.
26: The can container as set forth in claim 14, wherein: a width of
a bottom face of the score line is 0.03 mm to 0.1 mm.
Description
TECHNICAL FIELD
[0001] This invention relates to a can container such as an aerosol
can to be filled with contents.
BACKGROUND ART
[0002] Aerosol cans filled with a propellant as a high pressure gas
are used in the prior art of this kind of aerosol can is thrown
into the fire or left in a hot place over a prolonged period of
time, an inner pressure of the can container is raised
extraordinarily due to thermal expansion of a propellant. In this
case, a seamed portion where a can body and a bottom lid are
seamed, or an installation portion of the can body where a mountain
cap is mounted thereon may be demolished and the bottom lid of the
can container or the mountain cap is thereby blown off. In order to
prevent such an explosion of the can container resulting from a
pressure rise, a weakened portion is formed to release the inner
pressure of the can container. The weakened portion is to be
ruptured when the inner pressure of the can container exceeds a
certain value so that the can container is deformed. Examples of
this kind of can containers are disclosed in Japanese Patent
Laid-Open No. 47-7686 (corresponding to U.S. Pat. No. 3,786,967)
and Japanese Patent Laid-Open No 48-49591 (corresponding to U.S.
Pat. No. 4,003,505).
[0003] Japanese Patent Laid-Open No 477-686 discloses a can
container, in which a plurality of scores is formed equiangularly
on a top of a seamed portion where a metal upper lid (i.e., a
mountain cap) and a metal body portion are seamed. According to
this container, when the inner pressure thereof is raised, the
upper lid is deformed to inflate before a bottom lid is blown off.
As a result, the scores are ruptured to relief the inner
pressure.
[0004] Japanese Patent Laid-Open No 48-49591 discloses a can
container comprising a weakened part at its bottom which is
enclosed by a plurality of scores so that the resistance thereof is
weakened. This weakened part deforms when the inner pressure
exceeds a certain level and the scores are thereby ripped.
According to this can container the scores are formed on the wall
of the bottom portion, and tearing of the scores takes place only
when the bottom portion is deformed outwardly (i.e., when the
bottom portion of the can container protrudes outwardly).
[0005] However, in case of the invention disclosed in Japanese
Patent Laid-Open No 47-7686, the scores are formed on the seamed
portion of the metal can container so that sealing characteristics
of the seamed portion is unstable. For this reason, the contents or
propellant may leak from the seamed portion in spite of the inner
pressure of the can is proper. Moreover, a rupture of the scores
may be induced by an impact or vibration in transit and this also
results in a leakage of the contents or propellant from the
ruptured portion. Further, if the can container is dropped
accidentally, the seamed portion may collide directly with the
ground and this makes the score lines formed on the seamed portion
easy to be ruptured. As a result of this, the contents may be
released even when the inner pressure is not high enough to rupture
the scores lines.
[0006] Meanwhile, according to the invention disclosed in Japanese
Patent Laid-Open No 48-49591, the scores are formed at the
periphery of the curved part of the bottom portion of the can
container. Therefore, in case the bottom portion is deformed to
protrude outwardly when the inner pressure exceeds a certain level,
a center and its vicinity of the bottom portion is displaced toward
the outer side of an axial direction of the can container, however,
a central domed wall itself is not deformed significantly. For this
reason, if the scores are formed at the periphery of the curved
portion of the bottom portion but situated comparatively near the
center, the scores may not be ruptured even when the bottom portion
is deformed to protrude outwardly.
DISCLOSURE OF THE INVENTION
[0007] The present invention has been conceived noting the
technical background as thus far described, and its object is to
provide a can container comprising an easily rupturable portion,
which is certainly ruptured to release a gas in the can in case an
inner pressure of the can is raised extraordinary and which is not
ruptured in any other case.
[0008] In order to achieve the above-mentioned object, according to
the invention, there is provided a can container, which has an
annular ground contacting portion formed at a lower end of the can
container and a domed portion protruding inward of the can
container from an inner circumferential face of the annular ground
contacting portion, characterized in that: an easily rupturable
portion, which is ruptured when an inner pressure of the can is
raised extraordinary and the domed portion is thereby deformed to
protrude outward of the can container, is formed on an outer face
side of the domed portion and situated in the close vicinity of an
outer circumferential portion of the domed portion continuing into
the annular ground contacting portion.
[0009] According to the invention, the easily rupturable portion
may also be formed radially inward of the outer circumference of
the domed portion within a predetermined range.
[0010] According to the invention, the easily rupturable portion
may be a score line whose longitudinal section is an inverted
trapezoidal shape formed by a pair of inclined lateral faces which
are tapered from the face side toward the inner face side of the
domed portion and a bottom face connecting end portions of the
lateral faces at the inner face side of the domed portion.
[0011] According to the invention a planar shape of the easily
rupturable portion is an approximate semicircular shape, and end
portions thereof may be extended approximately in the radial
direction of the can container.
[0012] Therefore, according to the invention, when the inner
pressure of the can container is raised extraordinary by heat or
the like the domed portion is inflated and deformed to protrude
outwardly of the can container, within the outer circumferential
portion of the domed portion formed on the bottom side of the can
container (i.e. a lower edge of the domed portion continuing into
the annular ground contacting portion which is to be contacted
directly with the ground when the can container stands upright). As
a result the easily rupturable portion is ruptured to release the
contents of the can container For this reason a gas venting can be
achieved without blowing apart a piece of the can container, when
the inner pressure is raised extraordinary. In addition since the
easily rupturable portions are formed in the close vicinity of the
outer circumferential portion of the domed portion where the degree
of deformation resulting from inflation is great the easily
rupturable portions can be ruptured certainly when the domed
portion is inflated. The easily rupturable portions can be prevent
from being ruptured unexpectedly by dropping impact by forming them
on the outer face side of the domed portion in the close vicinity
of the outer circumferential portion of the domed portion in
comparison with the case in which the easily rupturable portions
are formed on the annular ground contacting portion which is likely
to collide directly with the ground if the can container is dropped
accidentally.
[0013] Also, according to the invention, since the easily
rupturable portions are situated radially inward of the outer
circumferential portion of the domed portion within a predetermined
range, the easily rupturable portions can be ruptured more
certainly.
[0014] Moreover, according to the invention, the cross-sectional
shape of the easily rupturable portions is an inverted trapezoidal
shape formed by a pair of inclined lateral faces and a bottom face
connecting the inclined lateral faces. This means that the a
clearance is created between the inclined lateral faces in the
amount of the bottom face when the inner pressure is raised to a
certain level by heat or shock and the domed portion is thereby
inflated little bit outwardly. For this reason, the easily
rupturable portion will not be ruptured undesirably.
[0015] Further, according to the invention, since a planar shape of
the easily rupturable portion is an approximate semicircular shape
and end portions thereof are extended approximately in the radial
direction of the can container, the semicircular portion enclosed
by the ruptured easily rupturable portion is easy to pop up
outwardly when the domed portion is deformed to protrude outwardly
and the easily rapturable portion is thereby ruptured, in
comparison with the case in which the easily rapturable portion is
formed linearly. For this reason, the pressure in the can container
can be relieved promptly. Additionally, since the end portions of
the easily rupturable portion are not directed to the adjoining
easily rupturable portion in the circumferential direction, the
rupture of the easily rupturable portion will not attack to the
adjoining easily rupturable portion even if the propagation of the
rupture extends beyond the end portion of the easily rupturable
portion For this reason, the domed portion will not be fractured
partially.
[0016] In addition to the above, according to the invention, it is
preferable to situate at least a portion of the easily rupturable
portion within the range of 3 mm form the outer circumferential
portion of the domed portion. Also, a width of a bottom face of the
score line is preferably 0.03 mm to 0.1 mm.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a bottom view showing a can container of the
invention.
[0018] FIG. 2 is a view showing a situation of the easily
rupturable portion of the can container illustrated in FIG. 1.
[0019] FIG. 3 is a longitudinal sectional view showing the domed
portion of the invention.
[0020] FIG. 4 is an enlarged view showing the domed portion
illustrated in FIG. 3.
[0021] FIG. 5 is an enlarged view of V portion in FIG. 4.
[0022] FIG. 6 is a longitudinal sectional view showing the can
container of the invention.
[0023] FIG. 7 is a front view showing the can container of the
invention.
[0024] FIG. 8 is a bottom view showing another example of the can
container of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Hereinafter, embodiments of the present invention will be
explained with reference to the accompanying drawings. FIGS. 6 and
7 respectively shows a metal can container such as an aerosol can
which is filled with a propellant as a high pressure gas. The can
container (i.e., a main body) 1 comprises a cylindrical metal can
body (i.e., a trunk portion) 2. An (not shown) aerosol valve member
is attached to one of the end portion of the can body 2, and a disc
shaped metal bottom lid (or can lid) 3 is fixed to another end
portion of the can body 2 by a seaming method. Contents to be
filled in the can container 1 can be exemplified by cosmetics, an
insecticide, a medical agent, a detergent, coating compositions, a
lubricant, foods and so on, and a high pressure gas is also filled
therein as a propellant.
[0026] A main material of the can body and the can lid of the can
container according to the invention is a metal material, in which
a proper surface treatment or plating is applied according to need
after the process of rolling. At least a metal material, in which a
resin coating is applied to a surface to be contacted with the
contents can be used. As a metal sheet material, steel sheet
materials, e.g., a pure aluminum or aluminum alloy sheet, an
electrolytic chromate treated steel sheet a nickel-plated steel
sheet, a tin plated steel sheet or the like can be used. Meanwhile,
as to the resin coating, coating composition as exemplified by an
epoxy-phenol resin an epoxy-acrylate resin, a polyvinyl chloride
series resin or the like, and a resin film composed of one or more
thermoplastic resin(s) as exemplified by a polyethylene,
polypropylene, polyester, polyamide, ionomer or the like, can be
suitably used in view of corrosion resistance and workability.
[0027] The can body 2 is formed by forming a seamless can by
drawing and ironing a thin metal sheet and a bottomed cylindrical
portion 2A which is diametrically smaller than the can body 2 is
formed by drawing the bottom side of the seamless can. Then, an
opening end of the can body 2 and the leading end of the bottomed
cylindrical portion 2A are trimmed, and an opening curled portion
2B to which an aerosol valve member is mounted is formed on the
bottomed cylindrical portion 2A side. Further, a flange portion 2C
which is to be seamed with the bottom lid 3 is formed on the
opening end of the can body 2. On the other hand, the bottom lid 3
is formed by forming a score line L as an easily rupturable portion
5 on the metal sheet material and punched out into a disc shape,
and then a press forming is applied thereto. The bottom lid 3
comprises a domed portion 3A, which protrudes inward of the can
container 1 when seamed with the can body 2 and whose longitudinal
section is arcuate, and a flange portion 3B to be fixed with the
can body 2 by a seaming method.
[0028] As illustrated in FIG. 1, score lines L, whose planar shape
is semicircle are formed on the outer face side of the can
container 1 in the vicinity of an outer circumferential portion 3C
continuing into the flange portion 3B. More specifically four score
lines L are formed equiangularly on the radially outermost portion
of the domed portion 3A. Each score lines L functions as the easily
rupturable portion 5 which is to be ruptured when the domed portion
3A is deformed. In FIGS. 1 and 2, the score lines L are situated at
the radially outermost portion of the bottom lid 3 in the close
vicinity of the outer circumferential portion 3C of the domed
portion 3A within a range of 3 mm from the outer circumferential
portion 3C, and both end portions of the score line L are directed
radially inward of the bottom lid 3. Here, a two-dot chain line M
in FIG. 2 represents a state where the score line L contacts with
the outer circumferential portion 3C of the domed portion 3A.
[0029] A shape of a longitudinal section of the score line L shown
in FIGS. 4 to 5 is an inverted trapezoidal shape formed by a pair
of inclined lateral faces 5A which are tapered from the outer face
side of the bottom lid 3 (or the can container 1) toward the inner
face side thereof and a bottom face 5B connecting lower end
portions of the lateral faces 5A substantially in parallel with the
bottom lid 3. According to this embodiment, a thickness of the
domed portion 3A of the bottom lid 3 is 0.3 mm, a residual
thickness underneath the score line L is 0.15 mm, a width of the
bottom face 5B is 0.06 mm, and an opening degree of the pair of
inclined lateral faces 5A is 50-degree. Additionally a pressure
capacity of the bottom lid 3 is degraded if the score lines L are
formed too many. For this reason it is preferable to for 2 to 10
score lines L in the circumferential direction of the bottom lid 3
at approximately even interval, within the above-mentioned
values.
[0030] The can container of the present invention shown in FIG. 6
is formed by attaching the bottom lid 3 to the can body 2 by a
seaming method, and a seamed portion 3D, where the can body 2 (or
the flange portion 2C) and the bottom lid 3 (or the flange portion
3B) are seamed together, corresponds to the annular ground
contacting portion of the present invention. The seamed portion 3D
comprises an annular ground contacting face which is to be
contacted with a floor or a table directly and inner and outer
circumferential faces 3E and 3F extending from a circumferential
portion of the ground contacting face near-vertically. An upper end
of an inner circumferential wall of the seamed portion 3D and the
outer circumferential portion 3C (i.e., a lower end of the domed
portion 3A) are connected with each other.
[0031] As an another embodiment of the present invention shown in
FIG. 8, an auxiliary score lines 6 pay also be formed radially
inward of each score line L situated in the close vicinity of the
outer circumferential portion 3C of the domed portion 3A. A
residual thickness under the auxiliary score line 6 is thicker than
that under the score line L. In this case, a stress concentration
at the score line L as forming the score lines can be relaxed by
forming the auxiliary score line 6 in addition to the score line L.
For this reason, the score line L is prevented from being thinned
partially too much and from suffering a crack. If the score line is
damaged when it is formed, such damage may get more serious as a
result of forming the domed portion 3A, especially in case of
forming the domed portion 3A after forming the score line.
[0032] Consequently, the resin film covering the inner face of the
score line may tear and the score line itself may crack. However,
it is possible to avoid such disadvantages by forming the auxiliary
score line 6.
[0033] According to the can container of the present invention,
when the inner pressure of the can container 1 is raised
extraordinary by heat or the like, the domed portion 3A is inflated
and deformed to protrude outwardly of the can container 1, within
the outer circumferential portion 3C around the domed portion 3A of
the bottom lid 3. At the moment, any of the score lines L formed in
the close vicinity of the outer circumferential portion 3C of the
domed portion 3A is ruptured to release the (not shown) contents
inside of the can container 1. For this reason, the seamed portion
3D where the can body 2 and the bottom lid 3 are seamed will not be
demolished so that the bottom lid 3 will not be blown off.
[0034] When the domed portion 3A is deformed to protrude outwardly
the center portion of the domed portion 3A is displaced outwardly
(i.e., downwardly) in the axial direction of the can container 1
but the wall surface of the domed portion 3A itself is not deformed
significantly. However, the wall surface in the close vicinity of
the outer circumferential portion 3C of the domed portion 3A is
deformed significantly, more specifically, it is elongated inwardly
in the radial direction of the domed portion 3A and outwardly in
the axial direction of the can container 1. According to the prior
art inventions, the score line L is not ruptured when the domed
portion 3A is deformed to protrude outwardly even if the score
lines L are formed in the vicinity of the center portion of the
domed portion 3A. On the other hand, according to the present
invention, score lines L are formed in the close vicinity of the
outer circumferential portion 3C of the domed portion 3A. For this
reason, it is possible to rupture any of the score lines L
certainly when the domed portion 3A is deformed to protrude
outwardly. It is to be especially noted that it is preferable to
situate at least a portion of the score lines L within the range of
3 mm from the outer circumferential portion 3C of the domed portion
3A inwardly in the radial direction.
[0035] Therefore, it is possible to rupture the score line L
certainly by forming the score lines L within the above-mentioned
range. Moreover, the score lines L are formed in the close vicinity
of the outer circumferential portion 3C of the domed portion 3A,
therefore the score line L can be prevented from being ruptured
unexpectedly by a drop impact even when the can is dropped
accidentally, in comparison with the case in which the score lines
are formed on the seamed portion 3D as the annular ground
contacting portion which is to be contacted directly with the
ground. Further, according to this embodiment, the longitudinal
sectional shape of the score line L is an inverted trapezoidal
shape, and the bottom face 5B is formed to connect the inclined
lateral faces 5A. Therefore, the score line L will not be ruptured
undesirably even if the inner pressure of the can container 1 is
raised to a certain level by heat or impact to inflate the domed
portion 3A slightly outward.
[0036] Additionally, the bottom face 5B cracks when the bottom lid
3 is deformed to protrude outwardly by a rise in the inner pressure
of the can container 1 so that the inclined lateral faces 5A are
brought into contact with each other. That is, provided that the
lower end portions of the inclined lateral faces 5A of the score
line L are contacted directly with each other without interposing
the bottom face 5B therebetween for example, the inclined lateral
faces 5A may be brought into contact with each other to rupture the
score line L even if the inner pressure of the can container is not
high enough to deform the bottom lid 3 to protrude outwardly but
the domed portion 3A is slightly inflated outwardly.
[0037] On the other hand, according to the can container of the
present invention, the longitudinal section of the score line L is
an inverted trapezoidal shape comprising the bottom face 5B.
Therefore, even if the domed portion 3A is deformed little bit
outwardly, the bottom face 5B creates a clearance between the
inclined lateral faces 5A. For this reason, the inclined lateral
faces 5A are not brought into contact with each other immediately
so that the score line L will not be ruptured undesirably even if
the inner pressure of the can container 1 is raised little bit. As
mentioned above, the score line L is ruptured by a slight
deformation of the bottom lid 3 if the width of the bottom face 5B
is too narrow, and to the contrary, it is difficult for the score
line L to be ruptured if the width of the bottom face 5B is too
wide. For this reason, the width of the bottom face 5B is
preferably within the range from 0.03 mm to 0.1 mm.
[0038] As also mentioned above, according to the present invention,
a planar shape of each score line L is semicircle, and end portions
thereof are extended approximately in the radial direction of the
can container 1. Therefore, the semicircular portion enclosed by
the ruptured score line L is easy to pop up outwardly when the
domed portion 3A is deformed to protrude outwardly so that the
score line L is ruptured, in comparison with the case in which the
score line is formed linearly on the bottom lid. For this reason,
it is possible to release the inner pressure of the can container 1
promptly. Additionally, since the end portions of the score line L
are directed approximately in the radial direction of the can
container 1, the bottom lid 3 will not be fractured partially even
if a rupture of the score line L resulting from a rise in the inner
pressure of the can container 1 extends beyond the end portion of
the score line L so that the bottom lid 3 cracks. To the contrary
provided that the end portions of the score line L are directed in
the circumferential direction, a propagation of a rupture of the
score line L would connect to the end portion of adjoining score
line L, in case the score line L is ruptured and such rupture
extends beyond the end portion thereof to crack the bottom lid 3.
As a result, a disc shaped fragment of the bottom lid 3 may be
separated therefrom.
[0039] On the other hand, according to the can container of the
present invention, the end portions of the score line L are
directed approximately in the radial direction of the can container
1. Therefore, circumferentially situated score lines L are not
positioned on the extension of the end portions of the adjoining
score line L. For this reason, the bottom lid 3 will not be
fractured partially even if a rupture of the score line L extends
beyond the end portion thereof and cracks the bottom lid 3. In
addition, according to the present invention, not only the can
container in which the bottom lid 3 is seamed with the can body 2,
but also a can container in which a can body and a bottom lid are
formed integrally may be used. Moreover, not only an aerosol can
but also a bottle-shaped can in which a threaded portion is formed
on one of the end portions of the can body 2.
INDUSTRIAL APPLICABILITY
[0040] This invention can be utilized in the field of manufacturing
aerosol cans or cans for manufacturing aerosol cans.
* * * * *