Note: Descriptions are shown in the official language in which they were submitted.
This invention rel~*es to a thin-walled bottle fabricated from
synthetic resin, more particularly to such bottle which is ætabilized in its
upright standing position.
Heretofore, glass bottles have been popularly used as container
bottles for carbonated drinks, refrigerants and the like. However~ such
glass bottles, because of their weight, involved the problems of high trans-
portation cost and inconvenience in handling.
In order to alleviate such problems, there has been developed a
light-weight thin~~alled bottle which is blow-molded from a synthetic resin
material. The body portion of such bottle is formed cylindrical while the
bottom wall is bulged out spherically downwards. Thus, the blow-molded bot-
tle is biaxially oriented and can maintain the excellent properties and dura-
bility of the synthetic resin, so that such bottle, although thin-walled, had
no problem in strength.
However, since the bottom wall o~ the bottle is bulged out spher-
ically downwards, such a bottle can not stay in its upright position unless a
separately pro~ided assis-ting leg element is used. Use of such an extra leg
element results in both increased manufacturing costs and an unseemly external
appearance for the bottle. Attempts have been made to form an integral pro-
tuberant leg element at the periphery of the bot-tle but~ in this case, the
underside of the leg portion might become unduly thin walled and liable to
break, and thus insufficient strength is provided at the bottom portion of
the bottle.
In order to o~ercome such problems, the possibilit~ of shaping the
bottle bottom wall inwardly to form a conical inward rise or kick while form-
ing undulations at the peripheral portion of the bottom wall, or the ground-
contacting portion of the bottle. In this case, although the bottle bottom
portion is su~iciently strengthened ~wing t~ the rib~lîke ~unction o~ the
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undulant peripheral po.rtion, there st.ill is involved a difficult
problem. I-t is required for withstanding the internal pressure in
the bottle to lessen the diameter of -the basal portion of the
conical rise, which basal portion defined the inner diameter of the
ground-contacting portion of the bottle~ but if such basal portion
is reduced in diameter, the stability of the bottle in its stand-
ing position is impaired and the bottle becomes prone to fall down
particularly when the bottle is empty because the centroid thereof
is positioned high. In other words, when this type of inward kick
is formed at the bottle bottom, the annular protuberant portion
defined by the basal portion of said kick becomes the ground-con-
tacting portion of the bottle, so that if the diameter of such
portion is small, the bottle becomes unstable when it is in its
standing position. Therefore, when such bottles are carried on a
conveyor for filling them with a liquid, it is found difficult to
keep them standing stably on the conveyor throughout the bottling
operation.
This invention seeks to provide a large-diameter annual
ground-contacting portion at the bottom of a synthetic resin bottle
to allow stable standing of the bottle. This invention also seeks
.~ to provide a synethetic resin bottle which is so constructed that
when the bottle is empty, the outer peripheral portion alone of
the bottle bottom is brought into contact with the ground so as to
be able to stand stably, and when the bottle is full, all the area
of the hottom portion is brought into contact with the ground so
that it can stand upright stably. This invention further seeks to
provide a synthetic resin bottle with a large-diameter annular
ground-contac~ing portion at the bottom and also provide inside there-
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of with a small-diameter conical rise with stepped portion there-
between to provide a greater endurance agains-t internal pressure
of the bottle.
The invention comprises a synthetic resin thin-walled
bottle having a neck portion, a biaxially oriented body wall por-
tion extending downwardly from the neck portion and a bottom wall
portion connected to the lower extremity of said body wall portion
through a body wall section which extends downwardly and inwardly
to said bottom wall portion, the bottom wall portion of said
bottle having an upwardly projecting rise having a conical lower
portion and an annuar basal portion connected to said section and
said rise through a substantially planar annular interconnect area,
said section having spaced on the circumferential periphery there-
of a plurality of rounded bulges projecting outwardly from said
section, each of said bulges having an underside surface positioned
more outwardly than said annular interconnect area, the underside
surface of said bu].ges being annularly arranged and forming an out-
er ground-contacting surface for said bottle.
In the attached drawings:
Figure 1 is a sectional view, with part broken away, of
a syn-
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thetic resin thin-~alled bottle in an e~bodiment of this invention;
Figure 2 is a l)o~tom view of the bottle of figure 1;
Figure 3 is a sectional view, with parts broken away, of a synthet-
ic resin thin-walled bottle in another embodiment of this invention,
~ igure 4 is a bottom view of the bottle of figure 39
Figure 5 is a sectional view, with parts broken awa~ of a synthet-
ic resin thin-walled bottle in still another embodiment o~ this invention,
and
Figure 6 is an enlarged sectional view of the bottle of Figure 5.
Described first is a first embodiment of this invention with refer-
ence to Figures 1 and 2. The synthetic resin thin-walled bottle 1 of this
invention is made by first forming a parison from a synthetic resin by injec-
tion molding and then biaxially orienting said parison by blow molding. As
for the synthetic resin material used in this invention, a saturated poly-
ester resin is ~ound best suited, but other resins such as polypropylene and
polyvinyl chloride are also usable. The neck portion 2 of the bottle 1 does
not undergo biaxial orientation, that is, it remains as that of the parison.
The body portion 3 and the bottom ~all 4 are biaxially oriented to have a
large diameter.
The bottom wall 4 is raised up in~ardly to ~orm a conical kick 4a~
and the peripheral portion thereo~ forms an annular inner ground-contacting
portion 5. Also, a slant 3a is formed between the lo~er part of the body
portion 3 and said ground-contacting portion 5 at the lower end thereof. In
the entire area of said slant 3a are formed a plurality of equidistantly
spaced-apart outward bulges 6 which are each in the form of a longitudinally
elongated hollow, ~ith the underside of each said bulge 6 being formed flat
to serve as an outer ground-contacting portion 7. The outer ground-contact-
ing portions 7 are arranged continuous to and radially around the inner
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ground-contactine portion 5, and they are located on a same plane to allow
stable upright standl.ng of the bottle 1.
The conical kick 4a is sma.ll in diameter at its lowermost portion
so that it can well withstand in-ternal pressure in the bottle. Since the
basal portion of said conical kick l~a is small in diameter, the inner ground-
contacting portion 5 formed around said ba.sal portion is also small in diam-
eter, but as there are provided therearound a plurality of outward bulges 6
which form the outer ground-contacting portions ~, a large-diameter ground-
contacting area is provided at the bottom of the bottle. Therefore, the
standing position of this bottle is far more stabiliæed than the bottIe which
has no such outer ground-conta.cting portions.
Said plurality of outward bulges 6 at the lower part of the bo-ttle
body portion and the conical kick 4a at the bottle bottom produce a rib-like
function to provide the bottle with high strength. Also, the bottle prop-
erties are improved by the effect of biaxial orientation. If the bottle is
molded from a saturated polyester resin, there ta~es place no seepage of
harmful matter such as solvent in use, and also no noxious gas is produced
uhen the discarded bot-tle is burned.
Referring now to Figures 3 and 4, there is shown a second embodi-
ment of this invention. In this embodiment, the lower part of the bottlebody portion 3 is curved inwardly downwards to form a curved section 8, and
a plurality of longitudinally elongated outward bulges 9 are formed in said
curved section 8, with the outer peripheral part of each said bulge 9, being
projected sl.ightly downwardly to form a ground-contacting surface 10. The
bottom portion continuous to the lower ena of said curved section 8 is in-
wardly raised up to form a conical kick 11, with the basal end 12 thereof
merging into the ground-contacting portion 10 positioned downwardly thereof.
Thus~ the bottle of this second embodiment is formed with a conical
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kick 11 ~ith a small diameter, so that the bo-ttle bottom portion is provided
with high endurance against internal pressure in the bottle and also said
conical ~ick portion ]1 is enhanced in rigidity. Although the kick 11 is
thus small in ~iameter, the portion at which the bottle botto~ contacts the
ground when in its standing position is limited to the area 10 at the outer
periphery alone of the bottle botto~l, so that the standing position of the
bottle when empty is stabili~ed. Tdhen the bottle is empty, the center o~
gravity thereof is positioned higher than that of the full bottle, so that
if the inner peripheral area of the bottle bottom is designed to serve as
ground-contacting surface, the bottle tends to fall down when even a small
protuberance exists on the place where the bottle is to be rested in its
standing position, but such tendency is minimized by allowing contact of only
the outer peripheral portion of the bottle bottom with the place.
Although there are provided five bulges 9 at the lower part of the
bottle body portion in the embodiment sho~m in Figure 4, such bulges may be
pro~ided in any suitable number. It is also possible to form a reinforcing
rib or ribs ~or each such bulge 9.
Reference is now had to Figures 5 and 6 which illustrate a third
embodiment of this invention. This embodiment is designed to provide the
bottle with even higher stability in its upright standing position when the
bottle is empty. ~he bottom wall 4 of the thin-walled bottle 1 is raised up
inwardly of the bottle and the basal end thereof is formed into an annular
flat strip 13. Also, a plurality of longitudinally elongated outward bulges
14 are formed in the slant section 3a at the lower part of the bottle body
portion 3, with the underside o* each said bulge 14 serves as an outer ground-
contacting suxface 15. The outer ground contacting surface 15 is positioned
sligh-tly downwardly of said annular flat strip 13 with a s-tepped portion
therebetween. Said annular ~lat strip 13 is positioned at a higher level
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th~l the outer ground-contacting surface 15 and i5 not brought lnto contact
with the ground when the bottle is empty, but orLce the bottle is filled with
a liquid, said strip 13 is pressed down by the liquid weigm against its
elas-ticity to the same position as that of the outer ground-contacting sur-
face 15 and iB thereby brought into contact with the ground.
Thus, in this embodiment, since the conical kick l~a is formed with
a small diameter~ a higher strength is provided against internal pressure
than the bottle with a kick of a larger diameter, and also said kick 4a is
enhanced in rigidity because of sufficien-t orientation. Further, although
the conical kick 4a is small in diameter~ the outer ground-contacting surface
at which the bottom of the bottle when empty is brought into contact with the
bottle resting place is positioned even more outwardly than in the preceding
embodiments because of provision of the annular ~lat strip 13, so that the
upright standing position of the empty bottle is even more stabilized.
When the bottle is ~illed with a liquid~ the annular flat strip 13
is brought into contact with the bottle resting place by the liquid weight `~,
to form an annular inner ground-contacting surface, so that e~en when the
bottle is placed upright on a shelf consisting of a plurality of spaced-apart
crosspieces such as used in, a refrigerator, there is no possibility that the
plurality of outward bulges 1~ should get caught between the crosspieces,
thus assuring convenience of use of the bottle.
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