Note: Descriptions are shown in the official language in which they were submitted.
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PLASTIC BUCKET AND LID
Inventor: John W. Von Holdt, Sr.
BACKGROUND OF THE INVENTION
Many designs of plastic buckets and lids are
well-known, see for example the following patents of John
W. Von Holdt: Patent Nos. 4,375,948: 4,574,974;
4,512,494; 4,512,493: 4,452,382; 4,380,305: 4,308,970:
and 4,210,258.
Many containers, such as cans for food, paint
and other solvents and chemicals have also been made of
plastic, as shown in the above-cited patents. However,
plastic buckets of course lack the strength of metal
buckets, so that in many cases special designs of the
plastic buckets must be used to obtain, for example, a
desired level of hoop strength about the mouth of the
plastic bucket. This hoop strength is achievable in the
prior art by reinforcement in some manner of the mouth
area of the plastic bucket, typically involving an
annular portion that projects radially inwardly, which
reinforces the bucket.
However, buckets of this design typically
require a collapsible core for their molding, which adds
capital and operating expense to the operation, and also
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tends to slow the operation down. Likewise, collapsible
cores are subject to failure and other problems, which
further slows the efficiency of the operation.
In accordance with this invention, a plastic
bucket is provided which does not require manufacture by
the use of a collapsible core. At the same time, the
bucket has a desired amount of hoop strength, even a
plastic bucket which is of the shape of a conventional
metal paint can.
The bucket of this invention may carry a lid
which is attached to the annular lip of the bucket in a
manner which prevents removal by other than a tamper-
indicating manner. Basically, the lid cannot be removed
until a tear strip is torn away. Nevertheless, the lid
is still capable of reattachment to the bucket from time-
to-time as may be desired.
DESCRIPTION OF THE INVENTION
By this invention, a plastic bucket defines an
annular lip and an attachable plastic lid. The lid
defines a peripheral, outer annular wall which defines an
outer wall of an annular recess of the lid. The bucket
lip occupies the recess in locked, sealed relation with
the lid. The outer, annular wall of the lid may define
a lower edge which resides in an annular recess of an
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upper surface of a flange carried by the bucket. Thus
the lower edge of the outer, annular wall is in effect
"buried" and inaccessible to the action of a screw
driver, rendering the lid substantially non-removable
from the bucket without permanent alteration.
For opening, the outer, annular wall of the
bucket lid carries a circumferential tear strip for
removing at least part of the outer, annular wall to
permit removal of the lid in a manner which clearly and
permanently indicates that the lid has been removed, even
after replacement thereof on the bucket.
Preferably, the bucket also carries, below and
adjacent the flange of the plastic lid, diagonally
positioned strengthening ribs which are integral with the
bucket and which are disposed in crossing array. These
ribs are typically near the bucket lip, and contribute to
the hoop strength of the bucket adjacent the lip.
It is also preferred for the bucket to define
only one, single, annular undercut adjacent the bucket
lip, in which an annular section of the bucket extends
diagonally and radially inward. The degree of such
extension may be on the order of one-fourth to one-eighth
inch. Such a bucket design, when contrasted for example
with a bucket which has two or more annular, inwardly
extending undercuts such as shown in Letica U.S. Patent
No. 4,349,119, can be manufactured without a collapsible
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~°°core, while equivalently-sized buckets made in accordance
with
the latter-cited patent generally require manufacture by a
collapsible core.
Also, a modified version of the above container may
define an annular flange around the container, positioned to
abut the bottom of a container lid outer flange to prevent
removal of the lid. An outwardly projecting tab is defined as
part of the flange between a pair of radial lines of tearing
weakness in the flange. Thus, the tab can be pressed
downwardly, tearing the radial tearing weakness lines and
exposing a portion of the bottom of the outer lid flange to
facilitate opening.
Broadly speaking, the present invention may be
considered as providing a plastic bucket including an upright,
annular bucket wall terminating in an annular lip to form an
open bucket mouth, the bucket wall having an annular undercut
located adjacent an upper end of the bucket, the wall of the
undercut extending upwardly and radially inwardly along a
diagonal path, the wall extending generally vertically upwardly
at the upper end of the diagonal path to form an upright annular
section, the wall extending radially outwardly at an upper end
of the upright annular section to form an annular, horizontal
flange, and the annular lip comprising an upright, annular rim
extending upwardly directly from a top of the annular,
horizontal flange.
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DESCRIPTION OF THE DRA~nIINGS
Referring to the drawings, Fig. 1 is a perspective
view of a molded bucket and attached lid in accordance with this
invention;
Fig. 2 is an enlarged, fragmentary, transverse
sectional view through the bucket lip and the periphery of the
lid of the bucket, taken along line 2-2 of Fig. 1;
Fig. 3 is an enlarged, fragmentary, elevational view
of the lid and upper portion of the bucket of Fig. 1, showing a
portion of the tear strip;
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Fig. 4 is a fragmentary, enlarged, longitudinal
sectional view of another embodiment of a bucket and lid:
Fig. 5 is a fragmentary, enlarged, elevational
view of a portion of the bucket of Fig. 4:
Fig. 6 is a fragmentary, plan view of the top
of another embodiment of the molded bucket and attached
lid in accordance with this invention;
Fig. 7 is a fragmentary, elevational view of
the container and lid of Fig. 6; and
Fig. 8 is a sectional view taken along line 8-8
of Fig. 6.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to Figs. 1-3, a plastic bucket 10
having an attached lid 12 is shown, each of the lid and
bucket being manufactured by inj ection molding from known
plastic compositions.
Bucket 10 is shown to comprise an annular lip
l4 which defines the bucket mouth across which lid 12
extends. Lid 12, in turn, defines a peripheral, outer
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annular wall 16 which, with annular, inner lid wall 18
and annular bridging wall 20, defines an annular recess
which is occupied by bucket lip 14 in locked, sealed
relation with lid 12.
Outer, annular lid wall 16 also defines a
circumferential tear strip 22, which extends almost
completely about the circumference of lid wall 16,
terminating at one end with a free handle 24 which is
partly surrounded by a space 26, so that handle 24 may be
grasped and pulled to cause circumferential tearing of
the circumferential tear line 28. Upon removal of tear
strip 22, the remainder of outer wall 16 may be pried
outwardly with relative ease for opening of the lid.
Inwardly extending projections 30 are provided
in known manner, being intermittently spaced about the
periphery of lid wall 16 to engage the undersurface of
bucket lip 14, as shown in Fig. 1.
Thus, after removal of tear strip 22, the
bucket lid is readily opened and reclosed as desired.
Additionally, bucket 10 defines a plurality of
outwardly and diagonally extending ribs 32, which are an
integrally molded part of the bucket 10 and which
intersect each other in criss-cross relation. These ribs
are positioned entirely around the periphery of bucket
10, and serve to increase the hoop strength of the
bucket.
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Also, bucket 10 is shown to define three
outwardly extending, integral rings 34 which intersect
the diagonal ribs 32, and thus also contribute to
improving the bucket's hoop strength in the vicinity of
the bucket lip.
Thus, buckets 10 can be molded which, although
made of plastic, can have hoop strength that is
comparable with metal buckets, yet which are better than
metal buckets in their resistance to pop off of the lid,
when the bucket is dropped and the like. Appropriate
fins or vanes 36 may be provided to strengthen lid 12 as
may be desired. Also, internal fins or vanes 38 may be
provided to bucket 10 for a similar strengthening
purpose.
Also, it can be seen that bucket 10 defines
only one annular, diagonal undercut 39, so that rings 34
may be provided without exceeding the main diameter of
the bucket. This permits the use of such a bucket in
conventional filling machinery and the like. Also, such
a bucket, in which the inward extent of the undercut 39
is no more than about one-quarter inch, can be
manufactured with a mold core which is not collapsible.
The bucket of preferred designs as shown can be popped
off of the mold core.
Referring to Figs. 4 and 5, a molded bucket l0a
carries a lid 12a which is of generally similar design to
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the previous embodiment except as otherwise shown herein.
As before, lid 12a defines an outer annular
wall 16a which, in conjunction with inner annular wall
18a and annular bridging wall 20a, defines an annular
recess for the securance of bucket lip 14a.
In this particular embodiment, bucket lip 14a
is carried upon a flange 40 which extends outwardly and
is carried by the bucket. Flange 40 defines an annular
recess 42 in which the lower edge 44 of outer, annular
lid wall 16a is "buried", to prevent one who desires to
open the container from prying the lid 12a off of the
bucket with a screw driver or the like. Thus, lid 12a is
permanently attached to bucket l0a until the removal of
tear strip 22a is accomplished.
Tear strip 22a may be of similar design to tear
strip 22 of the previous embodiment. When it has been
circumferentially removed by tearing along tear line 28a
in similar manner, the remaining portion of outer,
annular wall 16a is easily removed either with the
fingers or a screw driver. Inwardly extending projection
30a may be continuous and annular, or it may be
intermittent along the circumference for easier opening
of lid 12a.
A single undercut 39a is provided in bucket 12a
also, similar to the previous embodiment. This provides
a recess in which diagonal vanes or ribs 46 may be
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provided, extending in a diagonal, criss-cross manner as
illustrated by Fig. 5. This provides significantly
increased hoop strength to bucket 12a. Also, a label 48
may be placed over the criss-cross ribs 46 if desired by
automatic label applying machinery.
The bucket and lid of this embodiment can be
manufactured without a collapsible core due to the
presence of only a single undercut 39a. The resulting
container is tamperproof because of the required use of
tear strip 22a to open it, and exhibits a high hoop
strength for avoiding inadvertent lid pop off when the
container is dropped or the like.
Referring to Figs. 6 through 8, a molded bucket
lOb carries a lid 12b which is of generally similar
design to the previous embodiments, except as otherwise
shown herein.
Lid 12b defines an outer annular wall 16b
which, in conjunction with inner annular wall 18b and
annular bridging wall 20b, defines an annular recess for
the securance of bucket lip 14b.
In this particular embodiment an external
annular flange 50 is carried adjacent bucket lip 14b, so
as to receive and to shield the bottom 52 of outer lid
flange 16b when lid 12b is carried on bucket lOb in
sealing manner, as particularly shown in Fig. 8. This
abutment of the bottom of lid annular wall 16b renders
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difficult the removal of lid 12b from container lOb.
To facilitate this removal, a radially
outwardly projecting tab 54 is defined as part of annular
flange 50. In the embodiment shown, projecting tab 54
extends radially outwardly a bit farther than the
remainder of annular flange 50, and is bracketed between
a pair of lines of radial tearing weakness 56.
Thus, to open the container, tab 54 may be
manually pressed down to tear the lines of weakness 56,
causing tab 54 to pivot downwardly around the
circumferential, thin hinge portion 58 to a depressed
position as shown in phantom in both Figs. 7 and 8. This
exposes the bottom 52 of outer wall 16b, which
facilitates the opening of the container by permitting
removal of lid 12b. Also, tamper indication of the
opening is provided by the tearing of radial lines 56, so
that, while the container can be reclosed, a permanent
indication of such opening remains.
A particular advantage of this embodiment is
that it may be used in conjunction with a conventional
lid, and the portion of the container or bucket which
tears remains with the container or bucket so that it
does not have to be separately disposed of.
Bucket lOb is similar in design to the previous
embodiments in that it may carry crossing diagonal ribs
32b at a position below flange 50. The crossing ribs 32b
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extend around the bucket, for providing hoop strength and
the like. Alternatively, crossing diagonal ribs similar
to ribs 46 may be used, positioned in a recess, as shown
in the embodiment of Figs. 4 and 5.
Bucket lOb may define a single, annular
undercut 39b which contains the ribs if desired, with the
undercut 39b extending inwardly from the container wall
by typically no more than about 1/4 inch to facilitate
molding of the bucket without a collapsible core.
The above has been offered for illustrative
purposes only, and is not intended to limit the scope of
the invention of this application, which is as defined in
the claims below.
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