U.S. patent application number 10/444616 was filed with the patent office on 2003-10-23 for multi-functional base for a plastic, wide-mouth, blow-molded container.
Invention is credited to Ogg, Richard K., Tobias, John W., Trude, Greg.
Application Number | 20030196926 10/444616 |
Document ID | / |
Family ID | 33489350 |
Filed Date | 2003-10-23 |
United States Patent
Application |
20030196926 |
Kind Code |
A1 |
Tobias, John W. ; et
al. |
October 23, 2003 |
Multi-functional base for a plastic, wide-mouth, blow-molded
container
Abstract
A blow molded container having a multi-functional base which
enables use of the container in both hot-fill operations and
pasteurization/retort operations and enables efficient vertical
stacking of like containers. To this end, a portion of the base is
capable of flexing upwardly and/or downwardly in response to
variations in pressures in a filled and sealed container.
Structurally, the base has a continuous or discontinuous concave
outer annular wall forming a continuous or discontinuous standing
ring and an inner annular wall functioning as a flex panel. The
inner annular wall connects outwardly to a plurality of radial webs
extending at an elevation above the standing ring and connects
inwardly to a central dimple. Preferably, the inner periphery of
the annular wall is heat-set and biaxially oriented.
Inventors: |
Tobias, John W.;
(Spartanburg, SC) ; Ogg, Richard K.; (Littlestown,
PA) ; Trude, Greg; (Seven Valleys, PA) |
Correspondence
Address: |
HOWSON AND HOWSON
ONE SPRING HOUSE CORPORATION CENTER
BOX 457
321 NORRISTOWN ROAD
SPRING HOUSE
PA
19477
US
|
Family ID: |
33489350 |
Appl. No.: |
10/444616 |
Filed: |
May 23, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10444616 |
May 23, 2003 |
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10124734 |
Apr 17, 2002 |
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6612451 |
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60284795 |
Apr 19, 2001 |
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Current U.S.
Class: |
206/509 |
Current CPC
Class: |
B65D 1/0284 20130101;
B65D 21/0231 20130101; B65D 79/0081 20200501 |
Class at
Publication: |
206/509 |
International
Class: |
B65D 021/00; B65D
085/62 |
Claims
1. A container comprising a blow molded plastic body having an
integrally formed base with a central annular wall having an inner
periphery connecting to an anti-inverting central dimple that
projects from said inner periphery of said inner annular wall, said
inner periphery being made of blow molded plastic material that is
heat-set and biaxially-oriented, said inner annular wall of said
base flexing upwardly and downwardly in response to variations in
pressures within the container, when capped and filled, without
undergoing unwanted permanent deformation.
2. A container according to claim 1, wherein said central dimple
includes an indented, substantially-circular surface having
indented hollow ribs formed therein.
3. A container according to claim 1, further comprising a plurality
of spaced-apart, radially-extending, indented ribs on said base
where said inner periphery of said central annular wall
interconnects to said central dimple.
4. A container according to claim 3, wherein said base has a
concave outer annular wall with an outer portion and an inner
portion forming a container standing surface therebetween.
5. A container according to claim 4, wherein said concave outer
annular wall is continuous.
6. A container according to claim 4, wherein said concave outer
annular wall is discontinuous.
7. A container according to claim 4, wherein said inner portion of
said outer annular wall has a support ridge formed therein above a
level of said container standing surface to facilitate vertical
stacking of containers having like bases.
8. A container according to claim 4, wherein said standing ring has
a diameter of at least about 3.7 inches, and said inner periphery
of said central annular wall is less than about 1.25 inches.
9. A blow-molded plastic container comprising an integrally formed
base made of blow molded plastic material, said base having: a
discontinuous concave outer annular wall having an outer portion
and an inner portion forming a standing ring therebetween; an inner
annular wall extending inwardly from said inner portion of said
outer annular wall, said inner annular wall having an inner
periphery and an outer periphery, said outer periphery having a
plurality of radial webs extending outwardly at an elevation above
said standing ring, and said inner periphery being made of blow
molded plastic material that is heat-set and biaxially-oriented;
and an anti-inverting central dimple projecting upwardly from said
inner periphery of said inner annular wall; said inner annular wall
being deflectable upwardly and downwardly in response to variations
in pressures within the container, when capped and filled, without
undergoing unwanted permanent deformation below the level of the
standing ring.
10. A container according to claim 9, further comprising a
plurality of spaced-apart, radially-extending, indented ribs on
said base where said inner periphery of said inner annular wall
interconnects to said central dimple.
11. A container according to claim 9, wherein said central dimple
has a plurality of spaced-apart, radially-extending, indented ribs
formed therein.
12. A container according to claim 9, further comprising a shoulder
extending radially inward on said inner portion of said outer
annular wall above a level of said standing ring to facilitate
vertical stacking of containers having like bases.
13. A container according to claim 9, further comprising a
thin-walled body extending upwardly from said outer annular wall
and having a blown wide-mouth threaded finish at an upper end of
said body.
14. A container according to claim 9, wherein said container and
base is made of PET, wherein said standing ring has a diameter of
at least about 3.7 inches, and said inner periphery of said inner
annular wall is less than about 1.25 inches and said outer
periphery of said inner annular wall is at least about 2.5
inches.
15. A container, comprising: a blow molded plastic body having a
circular base, a cylindrical sidewall projecting from said base,
and a threaded finish opposite said base; said base having a
discontinuous concave outer annular wall with an outer portion and
an inner portion forming a container standing surface therebetween,
said outer portion connecting to said sidewall; said base having an
inner annular wall extending inwardly from said inner portion of
said outer annular wall, said inner annular wall having an inner
periphery and an outer. periphery, said outer periphery connecting
to a plurality of radial webs which extend at an elevation above
said container standing surface and which connect to said sidewall,
and said inner periphery being made of blow molded plastic material
that is heat-set and biaxially-oriented; said base having an
anti-inverting central dimple projecting upwardly from said inner
periphery of said inner annular wall; and said inner annular wall
of said base flexing upwardly and downwardly in response to
variations in pressures in the container without undergoing
unwanted permanent deformation.
16. A container according to claim 15, further comprising a
plurality of spaced-apart, radially-extending, indented ribs on
said base where said inner periphery of said inner annular wall
interconnects to said central dimple.
17. A container according to claim 16, wherein said inner portion
of said outer annular wall has a support ridge formed therein above
a level of said container standing surface to facilitate vertical
stacking of containers having like bases.
18. A container according to claim 17, further comprising a cap for
sealing said finish, said cap having a top surface with an outer
edge and said outer edge of said cap being engagable with said
support ridge formed on a container having a like base to
facilitate vertical stacking.
19. A container according to claim 17, wherein said cylindrical
sidewall provides a cylindrical label panel having a plurality of
longitudinally spaced circumferential reinforcement grooves and
outlined by an upper and lower label bumper.
20. A container according to claim 17, wherein said body is made of
PET, said discontinuous outer annular wall of said base forms four
identical, equally spaced apart, arcuate supports, and said arcuate
extent of each arcuate support is greater than an arcuate extent of
each radial web.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of
co-pending U.S. Non-Provisional Application No. 10/124,734 filed on
Apr. 17, 2002 which claims the benefit of priority of U.S.
Provisional Patent Application No. 60/284,795 filed on Apr. 19,
2001.
FIELD OF THE INVENTION
[0002] The present invention relates to a base for a wide mouth
blow-molded plastic container, and more particularly, the present
invention relates to a multi-functional base structure which
enables use of the container in hot-fill, as well as
pasteurization/retort processing.
BACKGROUND OF THE INVENTION
[0003] Plastic blow-molded containers, particularly those molded of
PET, have been utilized in hot fill applications where the
container is filled with a liquid product heated to a temperature
in excess of 180.degree. F. (82.degree. C.), capped immediately
after filling, and allowed to cool to ambient temperatures. Plastic
blow-molded containers have also been utilized in
pasteurization/retort processes where a filled and sealed container
is subjected to thermal processing and is then cooled to ambient
temperatures. In both cases, the containers are typically provided
with vacuum absorption panels to accommodate volumetric changes in
the container as the contents of the sealed container are heated
and/or as the contents cool within the sealed container.
[0004] U.S. Pat. No. 6,439,413 issued to Prevot et al. and assigned
to Graham Packaging Company, L.P. discloses a hot-fillable and
retortable plastic wide-mouth blow-molded container having a
sidewall with a pair of flex panels.
[0005] Co-pending U.S. patent application Ser. No. 10/129,885 filed
on May 10, 2002 is the U.S. national phase of International
Application No. PCT/US00/31834, is assigned to Graham Packaging
Company, L.P., and discloses a pasteurizable wide-mouth container
having a novel base.
[0006] Other plastic wide-mouth containers having paneled sidewalls
are disclosed in U.S. Pat. Nos.: 5,887,739 issued to Prevot et al.;
5,261,544 issued to Weaver, Jr.; and 5,092,474 issued to Leigner. A
pasteurizable plastic container having paneled sidewalls and a
narrow neck finish is disclosed by U.S. Pat. No. 5,908,128 issued
to Krishnakumar et al.
[0007] Containers having non-paneled sidewalls and yieldable
endwall structures are disclosed in U.S. Pat. Nos. 4,642,968,
4,667,454 and 4,880,129 issued to McHenry et al.; 5,217,737 issued
to Gygax et al.; 5,234,126 issued to Jonas et al.; 4,381,061 issued
to Cerny et al.; 4,125,632 issued to Vosti et al.; and 3,409,167
issued to Blanchard. The above cited U.S. patents disclose
containers having various base structures.
[0008] The structure of a so-called footed base is disclosed, in
general, in U.S. Pat. Nos.: 4,355,728 issued to Yoshino et al.;
5,713,480 issued to Petre et al.; 3,727,783 issued to Carmichael;
4,318,489 issued to Snyder et al.; 5,133,468 issued to Brunson et
al.; 5,024,340 issued to Alberghini et al.; 3,935,955 issued to
Das; 4,892,205, 4,867,323 and Re. 35,140 issued to Powers et al.;
and 5,785,197 issued to Slat.
[0009] U.S. Pat. No. 4,321,483 issued to Dechenne et al. discloses
a base having slightly angled annular surface and a central conical
projection; and U.S. Pat. No. 4,386,701 issued to Galer discloses a
blow molded plastic drum having a base which is designed to stack
efficiently with the lid of a like drum.
[0010] While the above referenced containers and base structures
may function satisfactorily for their intended purposes, there is a
need for a plastic, wide-mouth, blow-molded container which is
particularly suited for packaging a variety of viscous and other
food products and which has a novel base structure that enables the
container to be utilized in hot-fill and pasteurization processes.
The base structure should be capable of accommodating increased
internal pressure experienced during pasteurization; capable of
accommodating vacuum formed in the sealed container during cool
down; capable of resisting unwanted inversion or like deformation;
and capable of efficient stacking with like containers.
OBJECTS OF THE INVENTION
[0011] With the foregoing in mind, a primary object of the present
invention is to provide a commercially satisfactory wide-mouth
blow-molded container that can be utilized in hot-fill applications
as well as pasteurization, or retort, applications for packaging
fluent, viscous and solid food products.
[0012] Another object of the present invention is to provide a base
structure capable of accommodating an increase in internal
container pressure when the sealed container is subjected to
thermal treatment and capable of accommodating vacuum during cool
down.
[0013] Still another object of the present invention is to provide
a hot-fillable and pasteurizable container having a base which
accommodates changes in internal pressure and volume and which
resists unwanted inversion and other deformation.
[0014] A further object of the present invention is to provide a
structure for a wide-mouth plastic container which can be
efficiently stacked, one on top of the other, with like containers
and which can be produced by means of high speed manufacturing
equipment in an economical manner that ensures consistent quality
and performance.
SUMMARY OF THE INVENTION
[0015] More specifically, the present invention provides a blow
molded plastic container having a base with a continuous or
discontinuous concave outer annular wall having an outer portion
and an inner portion forming a standing ring therebetween. The base
also includes an inner annular wall that extends within the outer
annular wall and above the standing ring. The inner periphery of
the inner annular wall is made of blow molded plastic material that
is heat-set and biaxially-oriented and connects to an
anti-inverting central dimple. Functionally, the inner annular wall
is capable of flexing upwardly and downwardly in response to
variations in pressures in a filled and sealed container without
undergoing unwanted permanent deformation. In addition, preferably
a shoulder extends radially inward on the inner portion of the
outer annular wall above a level of the standing ring to facilitate
vertical stacking of containers having like bases.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The foregoing and other objects, features and advantages of
the present invention should become apparent from the following
description when taken in conjunction with the accompanying
drawings, in which:
[0017] FIG. 1 is a perspective view of a container having a base
embodying the present invention;
[0018] FIG. 2 is an elevational view of the container illustrated
in FIG. 1;
[0019] FIG. 3 is bottom plan view of the base illustrated in FIG.
1;
[0020] FIG. 4 is a cross-sectional view of the base taken along
line 4--4 of FIG. 3;
[0021] FIG. 5 is a cross-sectional view of the base taken along
line 5--5 of FIG. 2 and illustrates a pair of containers in a
stacked arrangement;
[0022] FIG. 6 is a perspective view of a second embodiment of a
container having a base embodying the present invention;
[0023] FIG. 7 is an elevational view of the container illustrated
in FIG. 6;
[0024] FIG. 8 is bottom plan view of the base illustrated in FIG.
6;
[0025] FIG. 9 is a cross-sectional view of the base taken along
line 9--9 of FIG. 8; and
[0026] FIG. 10 is a cross-sectional view of the base taken along
line 10-- 10 of FIG. 7 and illustrates a pair of containers in a
stacked arrangement.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] The present invention provides containers, 10 and 100, which
are particularly suited for use as a jar for packaging food
products. For example, the containers 10 and 100 can be used to
package fluent or semi-fluent food products such as applesauce,
spaghetti sauce, relishes, sauerkraut, baby foods, and the like.
They can also be used to package a solid food product suspended in
a liquid brine, such as pickles. Thus, the containers, 10 and 100,
can be utilized for packaging various food products and can
withstand various fill and treatment operations, as will be
discussed.
[0028] The embodiment of the present invention illustrated in FIGS.
1-5 is a container 10 having a base 12, a substantially cylindrical
sidewall 14, and a wide-mouth threaded finish 16 which projects
from the upper end of the sidewall 14 via a shoulder 18.
Preferably, as illustrated, upper and lower label bumpers, 20 and
22, are located adjacent the shoulder 14 and base 12, respectfully,
and outline a substantially cylindrical label area 24 on the
sidewall 14. Thus, a label (not shown) can be attached to, and
extend completely around, the container sidewall 14. In addition,
preferably the sidewall 14 has a series of circumferential grooves
26 which reinforce the cylindrical shape of the sidewall 14 and
resist paneling, dents and other unwanted deformation of the
sidewall 14.
[0029] The container 10 is multi-functional since it can be
utilized in hot-fill as well as pasteurization/retort processing.
To accomplish this objective, the base 12 has a structure which is
capable of accommodating elevated internal container pressure
experienced during pasteurization/retort processing and which is
capable of accommodating reduced container volume experienced upon
cool down of a filled and sealed container after hot-fill or
pasteurization/retort processing. To this end, the base 12 flexes
downwardly in a controlled manner and to a desired extent when
pressure within the filled and sealed container is elevated, and
the base 12 flexes upwardly in a controlled manner and to a desired
extent when a vacuum develops within the filled and sealed
container.
[0030] Structurally, the base 12 includes a continuous or
discontinuous concave outer annular wall 28. In the illustrated
embodiment of base 12, concave outer annular wall 28 is
discontinuous and provides a plurality of spaced-apart, arcuate
supports 30 adjacent the outer periphery 32 of the base 12. Four
supports 30 are utilized in the illustrated embodiment; however,
two, three, five or more supports 30 could also be utilized. Yet
another alternative includes providing concave outer annular wall
28 as a continuous structure that forms a continuous standing
ring.
[0031] Each support 30 has an outer wall portion 34 which extends
upwardly toward the lower label bumper 22 and an inner wall portion
36 which extends upwardly and inwardly into the remaining base
structure as will be discussed. A standing surface 38 is formed at
the juncture of each outer and inner wall portions, 34 and 36.
Thus, a discontinuous support ring of the container 10 is provided
in the illustrated embodiment. Alternatively, as discussed above, a
continuous support ring can be provided.
[0032] An inner annular wall 40 extends within the concave outer
annular wall 28 and may, or may not, be slightly inclined relative
to the horizontal. For instance, the inclined inner annular wall 40
can extend upwardly and inwardly at an angle "A" relative to the
horizontal as it extends from its outer periphery 42 to its inner
periphery 44. By way of example, the inner annular wall 40 can
incline at an angle "A" in a range of about 5.degree. to about
6.degree. relative to a horizontal plane "P" extending through the
standing surfaces 38. Alternatively, the inner annular wall 40 can
be formed substantially planar and parallel to a horizontal plane
"P" extending through the standing surfaces 38.
[0033] The outer periphery 42 of the inner annular wall 40 merges
with the inner wall portion 36 and, in the illustrated embodiment,
with a plurality of spaced-apart, horizontally-disposed, radial
webs 46 located adjacent the outer periphery 32 of the base 12.
Each of the webs 46 extends between the supports 30 and connects to
the container sidewall 14 at an elevation above the horizontal
plane "P" extending through the standing surfaces 38. A base having
a continuous outer annular wall would not include webs 46.
[0034] The inner periphery 44 of the inner annular wall 40 merges
into an anti-inverting dome 48 which projects upwardly into the
container 10. In the illustrated embodiment, the inner annular wall
40 and anti-inverting dome 48 merge via an annular hinge 50. As
illustrated in FIG. 4, the anti-inverting dome 48 has a conical
lower portion 52 adjacent hinge 50 and a convex upper portion
54.
[0035] The inner annular wall 40 functions as a flex panel. To this
end, when the internal pressure increases within a filled and
sealed container, the inner annular wall 40 flexes downwardly as
shown in dashed lines "B" in FIG. 4 to accommodate the increased
pressure and prevent the sidewall 14 of the container 10 from
undergoing unwanted permanent distortion. In addition, the inner
annular wall 40 flexes upwardly to relieve vacuum when the contents
of a hot filled and capped container, or a filled, capped and
subsequently pasteurized container, cool to ambient. This is shown
in dashed lines "C" in FIG. 4. Thus, when the sealed container and
contents cool to ambient, the sidewall 14 is substantially
cylindrical and unchanged from its as-formed shape and is capable
of neatly supporting a wrap-around label without unwanted voids or
the like beneath the label. In addition, the sidewall 14 resists
ovalization and the base 12 provides a level seating surface which
is not subject to rocking or the like.
[0036] The anti-inverting dome 48, the supports 30 and the radial
webs 46 support the inner annular wall 40 and permit it to flex
only within a desired range of movement as illustrated by dashed
lines "B" and "C". For instance, the inner annular wall 40 flexes
downwardly due to an increase in pressure within the container, but
is prevented from complete inversion and failure by the
anti-inverting dome 48 which travels with the inner annular wall 40
but substantially maintains a constant shape regardless of the
internal pressure experienced within the container.
[0037] Another feature of the base 12 of the present invention is
that each inner wall portion 36 of the arcuate supports 30 has an
arcuate shoulder, or support ridge, 56 formed therein and spaced in
elevation from both the support surfaces 38 and the inner annular
wall 40 to facilitate vertical stacking of like containers 10. For
example, as illustrated FIG. 5, an upper container 10a is stacked
on a lower container 10b. The support ridge 56 in the base 12a of
the upper container 10a seats on the outer edge 58 of the upper
surface 60 of the lid 62 of the lower container 10b such that the
horizontal plane "Pa" extending through the standing surfaces 38a
of the upper container 10a extends a spaced distance beneath the
top surface 60 of the lid 62 of the lower container 10b.
[0038] By way of example, and not by way of limitation, the
container 10 according to the present invention preferably has a
height "H" of about 5.8 inches, a container outermost diameter "D"
of about 4.2 inches, and contain a capacity of about 32 fluid
ounces. The discontinuous standing ring formed by the standing
surfaces 38 has a diameter of about 3.6 inches, and the inner
annular wall 40 of the base 12 has an inner periphery 44 with a
diameter of about 1.6 inches and an outer periphery 42 with a
diameter of about 2.2 inches. The radial webs 46 are uniformly
spaced apart and separate each support 30 such that each support 30
is at least about 0.8 radians. In addition, each support 30 has a
slightly larger arcuate extent than that of each radial web 46.
[0039] A second embodiment of the of the present invention is
illustrated in FIGS. 6-10 as container 100. Container 100 has a
base 112, a sidewall 114, and a wide-mouth threaded finish 116
which projects from the upper end of the sidewall 114 via a
shoulder 118. Preferably, as illustrated, upper and lower label
bumpers, 120 and 122, are located adjacent the shoulder 114 and
base 112, respectfully, and outline a substantially cylindrical
label area 124 on the sidewall 114. In addition, preferably the
sidewall 114 has a series of circumferential grooves 126 which
reinforce the sidewall 114 and resist paneling, dents and other
unwanted deformation of the sidewall 114.
[0040] The container 100 is multi-functional since it can be
utilized in hot-fill as well as pasteurization/retort processing.
To accomplish this objective, the base 112 has a structure which is
capable of accommodating elevated internal container pressure
experienced during pasteurization/retort processing and which is
capable of accommodating reduced container volume experienced upon
cool down of a filled and sealed container after hot-fill or
pasteurization/retort processing. To this end, the base 112 flexes
downwardly in a controlled manner and to a desired extent when
pressure within the filled and sealed container is elevated, and
the base 112 flexes upwardly in a controlled manner and to a
desired extent when a vacuum develops within the filled and sealed
container.
[0041] Structurally, the base 112 includes a concave outer annular
wall 128 that is either continuous or discontinuous. In the
illustrated embodiment, base 112 has a discontinuous concave outer
annular wall 128 that provides a plurality of spaced-apart, arcuate
supports 130 adjacent the outer periphery 132 of the base 112. Each
support 130 has an outer wall portion 134 that extends upwardly
toward the lower label bumper 122 and an inner wall portion 136
that extends upwardly and inwardly into the remaining base
structure as will be discussed. A standing surface 138 is formed at
the juncture of each outer and inner wall portions, 134 and 136,
thereby forming a discontinuous support ring of the container 100.
In an additional contemplated embodiment of the present invention,
the concave outer annular wall 128 is provided as a continuous
structure that forms a continuous support ring.
[0042] An inner annular wall 140 extends within the concave outer
annular wall 128. The inner annular wall 140 has an outer periphery
142 and an inner periphery 144. The outer periphery 142 of the
inner annular wall 140 merges with the inner wall portion 136 of
each of the supports 130 and, in the illustrated embodiment, with a
plurality of spaced-apart, horizontally-disposed, radial webs 146
located adjacent the outer periphery 132 of the base 112. Each of
the webs 146 extends between the supports 130 and connects to the
container sidewall 114 at an elevation above the horizontal plane
"P" extending through the standing surface 138. In an embodiment of
the present invention in which the concave outer annular wall 128
is continuous, webs 146 are not provided. The inner periphery 144
of the inner annular wall 140 merges into an anti-inverting central
dimple 148.
[0043] The inner annular wall 140 functions as a flex panel. To
this end, when the internal pressure increases within a filled and
sealed container, the inner annular wall 140 flexes downwardly to
accommodate the increased pressure and to prevent the sidewall 114
of the container 100 from undergoing unwanted permanent distortion.
In addition, the inner annular wall 140 flexes upwardly to relieve
vacuum when the contents of a hot filled and capped container, or a
filled, capped and subsequently pasteurized container, cool to
ambient. Thus, when the sealed container and contents cool to
ambient, the sidewall 114 is substantially unchanged from its
as-formed shape and is capable of neatly supporting a wrap-around
label without unwanted voids or the like beneath the label. In
addition, the sidewall 114 resists ovalization and the base 112
provides a level seating surface which is not subject to rocking or
the like.
[0044] The base 112 of container 100 is specifically designed to
provide greater flexural movement than base 12 of container 10
discussed above so that it can be utilized in processes that
require relatively high hot-fill and/or pasteurization/retort
temperatures. Increasing flexure of the base 112 is accomplished by
providing a larger circular flat between the dimple 148 and the
arcuate supports 130. Thus, the inner annular wall 140 of container
100 is larger than the inner annular wall 40 of the container 10,
despite the containers 10 and 100 being of the same given size. To
this end, the diameter, size, or extent of the central dimple 148
is reduced relative to the size of dome 48, and the inner diameter
of the arcuate supports 130 is increased relative to that of
arcuate supports 30.
[0045] The relatively large flat provided by inner annular wall 140
provides greater flexure; however, it also is more prone to "roll
out", ie. becoming permanently deformed in an outwardly projecting
position when its contents are hot-filled or heated at relatively
high temperatures. This is because an amorphous ring of material is
created at the interconnection of the inner periphery 144 of the
inner annular wall 140 and the dimple 148 due to the reduced size
of the dimple 148. This ring of unoriented, non heat-set material
provides a weakened area that permits the base to "roll out" when
filled and sealed with contents at high temperatures.
[0046] The base 112 of the present invention overcomes the "roll
out" problem by providing a series of spaced-apart,
radially-extending, hollow, indented ribs 150 in the dimple 148
where the inner periphery 144 of the inner annular wall 140
interconnects to the central dimple 148. The structure provided by
the ribs 150 causes the material in this region to be stretched
during blow molding of the container 100 so that the ring of
material adjacent the interconnection of the dimple 148 and inner
annular wall 140 is both heat-set and bi-axially oriented to
structurally reinforce the base and prevent "roll out" of the base
112. If desired, the dimple 148 can be indented to a given extent
into the container 100 to provide additional stretching, and the
total number of ribs 150 can be three or more, such as six as
illustrated in FIG. 6. In addition, the shape and size of the ribs
can vary as long as the blow molded plastic material forming the
base at the interconnection of the dimple 148 and inner annular
wall 140 is bi-axially oriented and capable of being heat-set by
heated surfaces of a blow mold.
[0047] Thus, the inner annular wall 140 flexes downwardly when the
container is filled, capped and subjected to an increase in
pressure within the container, but is prevented from complete
inversion and failure due to the reinforcement ribs 150 formed in
the dimple 148 which travel with the inner annular wall 40 but
substantially maintain a constant shape regardless of the internal
pressure experienced within the container.
[0048] Another feature of the base 112 of the present invention is
that each inner wall portion 136 of the arcuate supports 130 has an
arcuate shoulder, or support ridge, 156 formed therein and spaced
in elevation from both the support surfaces 138 and the inner
annular wall 140 to facilitate vertical stacking of like containers
100. For example, as illustrated FIG. 10, an upper container 100a
is stacked on a lower container 100b. The support ridge 156 in the
base 112a of the upper container 100a seats on the outer edge 158
of the upper surface 160 of the lid 162 of the lower container 100b
such that the horizontal plane "Pa" extending through the standing
surfaces 138a of the upper container 100a extends a spaced distance
beneath the top surface 160 of the lid 162 of the lower container
100b.
[0049] By way of example, and not by way of limitation, the
container 10 according to the present invention preferably has a
height "H" of about 5.8 inches, a container outermost diameter "D"
of about 4.2 inches, and can contain a capacity of about 32 fluid
ounces. The discontinuous standing ring formed by the standing
surfaces 38 has a diameter of about 3.7 inches, and the inner
annular wall 140 of the base 112 has an inner periphery 144 with a
diameter of less than about 1.25 inches and an outer periphery 142
with a diameter of at least about 2.5 inches. The radial webs 146
are uniformly spaced apart and separate each support 130 such that
each support 130 is at least about 0.8 radians. In addition, each
support 130 has a larger arcuate extent than that of each radial
web 146.
[0050] Preferably, the containers 10 and 100 are blow molded from
an injection molded preform made of PET, PEN or blends thereof or
is extrusion blow molded of PP. In addition, the containers 10 and
100 may be multilayered including a layer of gas barrier material
or a layer of scrap material. Preferably, the finishes of the
containers are threaded, blow molded, and severed from an
accommodation feature formed thereabove.
[0051] The above described containers 10 and 100 are capable of
use, for instance, in hot-fill operations having fill temperatures
up to about 205.degree. F. As explained above, preferably container
100 having base 112 is utilized when temperatures approach or
exceed the 205.degree. F temperature level. The containers can also
be utilized in pasteurization processes wherein a cold solid
product, such as pickles, is combined within the container with
mildly heated brine at 120 to 140.degree. F. After the container is
capped, the filled container can be processed through a
pasteurization tank where temperatures approach about 212.degree.
F. so that the solid products in the sealed container are heated to
approximately 175.degree. F. for 15 minutes before the filled and
sealed container is cooled to ambient temperature.
[0052] While preferred containers and base structures have been
described in detail, various modifications, alterations and changes
may be made without departing from the spirit and scope of the
present invention as defined in the appended claims.
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