Note: Descriptions are shown in the official language in which they were submitted.
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PLASTIC CONTAINER wrn DOUBLE LOCK LID
AND TEAR BAND
FIELD OF THE INVENTION
[0002] This invention relates to plastic containers of the type comprising
a pail and a lid
which sealingly fits onto the pail without the need for a gasket and further
wherein the container
combination has two locks which hold the lid onto the pail and a
circumferential tear line which
allows one of the locks to be removed.
.BACKGROUND OF THE INVENTION
[0003] Plastic containers comprising the combination of an open top pail
and a lock-on
lid or closure are well known and have been in commercial use for shipping and
merchandising
various products in the United States for many years. The word "lock", as used
in this product
area, refers to an undercut-based snap fit between the pail and lid whieh
inhibits removal of the
lid, sometimes strongly enough to require the use of a tool or physical
alteration of the lid, to
achieve removal. Some containers have largely supplanted metal containers in
many areas . .
including adhesives, food products, paint, wallboard paste, spackling,
driveway sealant and other
products. The pail and lid are typically injection molded of a suitable
polymeric material such as
high density polyethylene or polypropylene. The seal between the pail and the
lid can be
achieved by providing a compressible 0,ring gasket or by molding a notch in
the top of the pail
rim flange and providing a corresponding bead in the underside of the inverted
U-shaped channel
of the lid which receives the rim bead of the pail. This later structure is
described in the
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published U.S. Application US 2002/0148846. Still another seal structure is
illustrated in the
expired patent to Richard Landis, United States Patent No. 4,418,833.
SUMMARY OF THE INVENTION
100041 The present invention provides a container comprising the
combination of an open
top pail and a lid, both preferably made of injection molded plastic such as
polyethylene or
polypropylene, wherein a good seal is provided between the pail and the lid
without the need for
either a gasket or special features such as rim beads and notches in the top
of the pail.
[0005] in general, this is achieved by providing a pail with a flangeless
top rim, and a lid
having a narrow inverted U-shaped peripheral channel defined by an inner
annular ring which is
reinforced by rddial ribs.
[0006] in addition, and in accordance with a preferred embodiment of the
invention,
multiple undercut-type locks are provided for securing the lid to the pail
wherein said multiple
locks comprise an upper lock comprising a continuous bead on the outer wall of
the container
immediately below the top edge and a plurality of widely circumferentially
spaced locking
segments on the inside surface of the inverted U-shaped channel formed by the
lid to Provide
widely spaced, discrete undercuts which receive the pail sidewall bead and
lock thereto. The
second or lower of the two locks is provided lower down on the container
sidewall at or near the
bottom of the outer skirt of the lid. This second lower lock may be
circumferentially
discontinuous, providing gaps which allow overfill material to drain.
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[0007] The lower lock is made removable by forming a circumferentially
extending
weakened area or "tear line" in the lid skirt such that the portion of the
skirt below the weakened
area can be tom away leaving only the upper lock in place. This manipulation
is typically carried
out by the end User. The tear line is located well below the upper lock,
thereby providing, after
removal of the lower skirt, enough remaining skirt to afford a good hand-hold
for subsequent
removal of the lid.
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According to one embodiment of the invention, an all-plastic container
structure comprises the combination of a solid plastic pail and a solid
plastic lid configured to
fit lockingly onto the pail. The pail has a substantially cylindrical sidewall
having an upper
annular crown portion extending to a rim and of a first diameter joined by an
annular neck to
a lower portion of a second diameter smaller than the first diameter, the
crown portion having
an unflanged annular rim having a thickness no greater than the thickness of
the sidewall; a
radially outwardly extending circumferential locking bead formed integrally
with said
sidewall immediately above the neck and on the outside surface of the
sidewall. An annular
collar is formed integrally and externally of said sidewall a substantial
distance below said
neck and having a top portion which extends outwardly and downwardly of said
sidewall, a
lower portion which extends downwardly substantially parallel to but outwardly
spaced from
said sidewall, said top portion and lower portion forming between them an
inwardly
extending annular recess The lid comprises a recessed central deck and,
integral therewith, a
raised annular peripheral portion forming an inverted U-shaped annular channel
which is
sized and configured to sealingly receive therein said rim and crown portion
and seal
therewith. The lid further comprises an outwardly flaring and downwardly
extending annular
skirt portion integrally depending from said peripheral portion and radially
spaced
substantially outwardly therefrom when the lid is placed on the pail. The
channel is defined
by parallel, spaced-apart radially inner and outer walls. A circumferential
tear groove is
formed in said lid skirt and has a starter tab located in an opening in said
skirt. An upper lock
is formed integrally with said lid within said channel and above said tear
groove, said
structure comprising an inwardly opening annular groove that lockingly
receives said locking
bead therein. A lower locking structure includes an annular, inwardly directed
projection on
the lowermost portion of said skirt, substantially below said tear groove,
said projection being
configured and spaced to extend radially into said annular recess close enough
to the
downwardly extending collar below said recess to inhibit access to the lower
end surface of
said projection. A plurality of circumferentially spaced, radially extending
integrally molded
plastic ribs are formed on the interior of said lid and extend radially
inwardly far enough to
reach under and be integrally attached to an underside of said center deck
portion to reinforce
inverted U-shaped channel of said lid.
[0008] In the preferred form, the upper lock is provided in two,
three or four discrete
and circumferentially spaced areas and indicia are carried on the top surface
of the lid to show
where
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the locking segments are located and to direct the user to apply a lifting
force in that area to
remove the lid from the container once the tear hand has been pulled away. In
the illustrated
embodiment, there are three such indicia in the forms of arrows with the
legend "LtEr" molded
into the top deck of the lid thereby to eliminate the need for a printing
function or the application
of a decal. However, both of these alternatives as well as other alternatives,
while not preferred,
=
are useable in accordance with the more detailed aspects of the present
invention.
[0009] Other applications of the present invention will become apparent
to those skilled
in the art when the following description of the best mode contemplated for
practicing the
invention is read in conjunction with the accompanying drawings.
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BRIEF DESCRIPTION OF THE DRAWING
[0010] The description herein makes reference to the accompanying
drawings wherein
like reference numerals refer to like parts throughout the several views, and
wherein:
[0011] Figure 1- is a perspective view of an all plastic injection
molded containei
comprising a pail and lid embodying the invention;
=
[0012] Figure IA is a perspective view of the Figure 1 container with
the lid removed;
[0013] . Figure 2-is a plan view of the inside surface of the lid from
the combination of
Figure 1;
[0014] Figure 3 is a plan view of the outside or top surface of the lid
of Figure 2;
1100151 Figure 4 is a side view in section of an enlarged portion of the
lid and pail
- showing how the upper and lower locks are formed;
[0016] Figure 5 is a side view in section showing the upper and lower
locks engaged; and
[0017] Figure 6 is a composite of side views in section showing how
containers stack on
top of one another.
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DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT
[0018]' Referring to the Figures there is shown an all plastic container 10
comprising the
combination of tapered cylindrical plastic pail 12 and an injection molded
lock-on plastic lid
14. In this illustrative embodiment the pail 12 and lid 14 are both injection
molded of high
density polyethylene, but other materials such as polypropylene may be used-as
alternatives.
[00191 The pail 12, which in this instance is a 3'A gallon pail but can be
made in a variety
of other larger and smaller sizes, comprises a tapered cylindrical side wall
16 extending upwardly
to an enlarged diameter collar 18 which is integral with, but is spaced
outwardly from, the wall
16 by ribs 32 and lies below the upper rim portion 26 as best shown in Figure
IA. The collar 18
runs circumferentially around the entirety of the pail 12 and has
diametrically opposite ear
portions 20 which receive a wire bail 22 having a ferrule type plastic handle
24 mounted thereon.
[0020] As shown in Figure IA the upper rim portion 26 of the open top
container 12 is
featureless; i.e., it has no notches, flanges or beads at the upper end.
However, approximately 1/2
to 3/4" below the upper rim portion 26 and on the inside surface of the side
wall 16 is a series of circumferentially
spaced bumps which protrude radially inwardly about 0.010" from the
surrounding surface to create a "pinch
seal" with the closure 14 as hereinafter described. On the outer sidewall
16sabout I inch below
the rim is a bead 28 which is circumferentially continuous around the pail 12
and forms part of
an upper lock to be described. Approximately 4 inches below the bead 28 is a
second radially
outwardly extending bead 30 which is preferably notched at six or eight evenly
spaced locations
and is integral and contiguous with the radially outstanding collar 18.
Reinforcing ribs 32 are
provided at circumferential intervals of about 1 1/8" around the pail.
Additional ribs 33 run
vertically between the outwardly flared wall below the bead 28 and the top of
the bead 30 to
stiffen the sidewall 16 and prevent deflection under stacking loads. Ribs 33
are integral with the
outer sidewall, run vertically and are spaced, for example, at 30 intervals
around the pals. Ribs
33 are approximately 4 inches long.
[0021] = Looking at. the lid 14, it comprises an inverted 'U-shaped
peripheral channel
portion 34 defining a downwardly opening and radially narrow, internal channel
36 Which snugly
and sealingly receives the top rim portion 26 of the pail 12 therein. The
inverted U-shaped
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channel peripheral portion 34 comprises an outer wall 38 and a downwardly
extending annular
inner wall 40 having circumferentially spaced reinforcing ribs 42 as shown in
Figures 2 and 4.
The outer surface of the lid has a recessed deck 44 with the tapered lead
surface 46 from the
peripheral channel portion 34 to make it easier.to stack one of the containers
on top of another of
like size and design.
[0022] In accordance with the invention, an upper lock comprises the
combination of the
bead 28 on the pail side wall 16 and three evenly circumferentially spaced
locking segments 48
forming undercuts 50 on the inside surface of the outer skirt 52 of the lid.
When the lid 14 is
firmly attached to and seated on the pail 12 the bead 28 fits Within the
undercuts 50 of the three
locking segments 48 to hold the lid 14 on the pail 12.
[0023] The lid 14 is originally molded with a long skirt including the
upper wall 38 and a
lower portion 52 separated=by a circumferential tear line 56 which is made
thin and weak enough
to allow the lower portion 52 to be torn off. A starter tab 60 is provided to
facilitate tearing.
Note that the tear line 56 is about I to 2 inches below the lock bead 28 which
fits into the
undercut notch 50 in the inner surface of the lid's upper skirt. This gives a
large handhold to
grasp the outwardly flared upper skirt above the tear line 56 after the lower
skirt 52 is removed as
shown in the top part of Fig. 6. At the bottom of the lower skirt 52 is
another inwardly-extending
flange or undercut 54 which snaps under the outer edge of the bead 30 to form
the lower lock.
Gaps 53 may be molded into the undercut 54 at regular intervals to drain any
overfill that might
be forced out of the pail when the lid 14 is first applied: This prevents
material from
accumulating between the pail sidewall 16 near feature 30 and the lower lid
skirt; a potentially
odor-causing condition if the fill material is a food product subject to
spoiling.
[0024] Further in accordance with the invention, indicia 58 comprising the
combination
of outwardly directed arrows and the legend "LIFT" are molded into the top
surface of the deck
44 to indicate exactly where the locking segments 48 are located such that a
user of the pail may
apply a lifting force in this area after the removal of the lower skirt 52 has
been achieved as
hereinafter described. Similar equivalent legends may be used.
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[0025] The lower skirt portion of the lid 14 comprises the
depending skirt 52 terminating
an undercut 54 which fits over and receives the bead 30 on the lower locking
collar portion 1.8 of
the pail side wall 16 when the lid 1.4 is placed on pail 12 and firmly seated.
However, a
circumferentially extending weakened area provided by a notch 56 allows the
lower portion of
the skirt 52 to be torn away. A starter tab 60 is provided as shown in Figure
IA in a cut-out area
62 For the purpose of facilitating the removal of the tear. band formed by the
skirt 52 so as to
eliminate the lower lock 30, 54.
[0020] In operation, the pail 12 and lid 114 are typically
injection molded at a suitable
plant site. Once they are shipped to the customer, the container 10 is filled
with product (not
shown). and the lid 14 is seated on the container 12 such that the upper rim
portion 26 of the =
container side wall extends fully and comactingly into the channel 36 and is
sealed by the pinch
seal at bump 27. There is a contact seal on both sides of the sidewall 16. The
upper lock 28, 50
snaps into place and the lower lock 30, 54 also snaps into place insecurely
hold the sealed lid 14
on the container 12. Similar containers 10 can be stacked and Shipped in the
product filled
condition withOut fear of leakage or the ingestion of unwanted air into the
interior of the
container 10.
[0027] When the user is ready to gain access to the product, the
starter tab 60 is broken
away from the lid portion 52 and the lower skirt 52 is removed. This
eliminates the lower lock
30, 54 and also provides evidence that the container 10 has been opened. Once,
the lower skirt 52
and the lower lock 30, 54, have been removed, the only lock holding the lid 14
to the pail 12 is
the segmented -upper lock 28, SO. This lock is relatively easily overcome
without the use of tools
by lifting the revealed edge of the lid 14 immediately adjacent. the indicia
arrows 58. The plastic
pail and lid combination is sufficiently flexible to permit the lid rim
channel sidewall 38 below
the lock 28 to be flexed outwardly and this overcomes the lock and permits the
lid 14 to be
removed from the pail 12. It also permits the lid 14 to be relocated and
relocked onto the pail 12
= using the three 120 spaced locks 28, 50. An audible "snap" occurs when
the lid 14 is fully re- =
seated, telling the user that a.good seal has been achieved.
[0028] = While the invention has been described in connection with
what is presently
considered to be the most practical and preferred embodiment, it is to be
.understood that the
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invention is not to be limited to the disclosed embodiments but, on the
contrary, is intended to
cover various modifications and equivalent arrangements included within the
scope of
the appended claims, which scope is to be accorded the broadest interpretation
so as to
encompass all such modifications and equivalent structures as it permitted
under the law.
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