Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION:
CONTAINER LID WITH TEAR-OFF STRIP
TECHNICAL FIELD
This invention relates to plastic containers, and in particular, to lids for
such containers where the lids have tear-off strips to facilitate the removal
of
the lids.
1 o BACKGROUND ART
In larger plastic containers, such as paint containers capable of holding
many litres of paint, it is necessary to provide a strong attachment and good
seal_between the container and the lid, especially for shipping purposes.
Usually, interlocking or inter-engaging flanges are provided on the lid and
the upper peripheral edge portion of the container to retain the lid on the
container. The difficulty is that the stronger is the engagement between these
interlocking flanges, and thus the stronger the attachment of the lid to the
container, the more difficult it is to remove the lid when it is desired to do
so.
Ideally, one would like to have good engagement between the lid and the
2 o container for shipping purposes, and some means for relieving or reducing
the force of engagement between the lid and the container when it is desirable
to remove the lid.
One method of accomplishing the above objectives is to provide the
lid with a tear-off strip that contains the lid locking flange that engages
the
container locking flange. When the lid is on the container, the engaged
locking flanges hold the lid securely onto the container. When it is desired
to
remove the lid, the lid tear-off strip is removed, so there is no longer any
locking engagement between the lid and the container. The lid is then easy to
remove.
3 o Sometimes, however, after the lid is removed, it is desirable to put the
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lid back on the container and still have a good seal between the lid and the
container. One way of achieving this result is shown in U.S. Patent No.
4,735,337 issued to John W. Von Holdt. In this patent, the lid outer skirt
that
contains the locking flange is provided with a zigzag tear line that defines a
tear-off strip. The tear line passes repeatedly through the locking flange, so
that upon removal of the tear-off strip, portions of the locking flange are
removed and only spaced-apart portions of the lid skirt locking flange
remain. These remaining portions then provide a lid lock with reduced
holding power, so that the lid can be removed and replaced.
so Another example of such a lid is shown in U.S. Patent No. 4,930,656
issued to Henry J. Blanchette. In this Blanchette patent, an intermittent
locking flange is provided on the lid peripheral skirt and an undulating
annular groove is provided to form a tear-off strip. When the tear-strip is
removed, the Iid ends up with bendable flaps containing the locking flanges,
and these flaps yield to permit easier removal and replacement of the Iid.
One difficulty with the prior art Von Holdt and Blanchette patents is
that the zig zag or undulating tear-off strips are difficult to remove. The
tooling to make the lids shown in these patents is also expensive because of
the complex nature. of the tear lines. The lid shown in the Blarichette patent
is
2 o also not as strongly retained on the container as would be desired,
because
only partial locking flanges are provided on the lid skirt.
DISCLOSURE OF THE INVENTION
In the present invention, a double locking flange is provided to
2 s securely hold the lid on the container. One of the locking flanges is
totally
removed along with the tear-off strip leaving a second, intermittent yieldable
locking flange for retention and resealing of the lid on the container.
According to the invention, there is provided a lid for a container
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having upper and lower peripheral, outwardly disposed locking flanges, the
flanges having undersides for locking engagement with the container lid.
The lid comprises a central portion and a peripheral annular skirt adapted to
overlie the container locking flanges. The annular skirt defines a peripheral
~ groove dividing the skirt into a skirt upper portion located adjacent to the
container upper locking flange, and a lower tear-off strip portion located
adjacent to the container lower locking flange. The skirt upper portion has
inwardly disposed intermittent locking flange segments adapted to engage the
underside of the container upper locking flange. The skirt upper portion also
z o is formed with thin membrane windows therein on either side of the locking
flange segments and bordering on the peripheral groove. Also, the tear-off
strip portion defines an inwardly disposed locking flange adapted to engage
the underside of the container lower locking flange, so that removal of the
tear-off strip portion leaves downwardly disposed thin membrane notches on
either side of the locking flange segments. Once the tear-off strip portion is
removed, a portion or portions of the skirt upper portion including one of the
locking flange segments may be pried out of engagement with the upper
outwardly disposed flange of the container, thereby enabling the lid to be
removed from the container.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention will now be described, by way
of example, with reference to the accompanying drawings, in which:
Figure 1 is a perspective view of a preferred embodiment of a lid
2 s according to the present invention shown mounted on a container;
Figure 2 is an enlarged perspective view, partly broken away, showing
the interlocking flanges between the lid and container shown in Figure 1;
Figure 3 is a further enlarged perspective view of the portion of Figure
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2 indicated by chain-dotted circle 3;
Figure 4 is an enlarged view of the portion of Figure 1 indicated in by
chain-dotted circle 4;
Figure 5 is an enlarged elevational view taken along lines 5-5 of
Figure 4;
Figure 6 is a sectional view taken along lines 6-6 of Figure 5;
Figure 7 is an elevational view similar to Figure 5 but showing a
modified thin membrane window;
Figure 8 is a perspective view ofthe upper portion of Figure 1
1 o showing one preferred embodiment of the locking flanges on the lid of the
present invention;
Figure 9 is a perspective view similar to Figure 8 but showing another
preferred embodiment of the locking flanges on the lid of the present
invention;
v Figures 10A to l OC are perspective views of embodiments of the lid
according to the present invention including indicator means on the outer
surface of the lid;
Figure 11 is a.perspective view of a first square shaped embodiment of
a lid of the present invention; and
2 o Figure 12 is a perspective view of a second square shaped embodiment
of a lid of the present invention.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring firstly to Figure 1, a preferred embodiment of a container lid
2 s according to the present invention is generally located by reference
numeral
10. Lid 10 is shown mounted on a container 12, but container 12 is not
considered to be part of the present invention per se. Lid 10 includes a
planar
central portion 14 and a peripheral annular skirt 16. The size of container 12
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is such that it holds typically from about 4 to 20 litres, and container 12
and
lid~l4 are most commonly made from plastic, such as polyethylene or
polypropylene. However, any plastic or other material can be used for lid 10
that has some resiliency, as will be described further below.
Referring next to Figures 2 and 3, container 12 is shown having an
upper, peripheral, annular, outwardly disposed locking flange 18 and a lower,
annular, outwardly disposed locking flange 20 spaced from or below locking
flange 18: Locking flanges 18, 20 have respective undersides 22, 24 for
locking engagement with lid 10, as described further below. Container 12
s o also has a further peripheral annular flange 26 which forms the rim or
brim of
container 12, and which is located in an annular sealing groove 28 in lid 10
located between the lid central portion 14 and the peripheral annular skirt
16.
When lid 10 is located.on container 12, the container annular flange 26 is
wedged into lid sealing groove 28 to provide a good seal between the
container and the lid. In other words, sealing groove 28 sealingly engages the
rim 26 of the container. If desired, a gasket (not shown) can be used in
groove 28, or groove 28 can be smaller than that shown in the drawings.
As seen best in Figure 3, the lid annular skirt 16 overlies the container
locking flanges 18, 20. Annular skirt 16 defines or has an annular groove 30
2 o which divides skirt 16 into a skirt upper portion 32 located adjacent to
the
container upper locking flange 18, and a lower tear-off strip portion 34
located adjacent to the container lower locking flange 20. Annular groove 30
can be on the inside surface of annular skirt 16 or the outside surface of
this
skirt, or partially in both, as shown in Figure 3.
As seen best in Figures 3 and 4 to 6, the skirt upper portion 32 is
formed with inwardly disposed intermittent locking flange segments 36
which are adapted to engage the underside 22 of the container upper locking
flange 18. Similarly, the tear-off strip portion 34 defines or has an inwardly
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disposed locking flange 38 which is adapted to engage the underside 24 of
the container lower locking flange 20.
As seen best in Figures 4, 5 and 6, skirt upper portion 32 is formed
with triangularly shaped thin membrane windows 40 therein on either side of
the locking flange segments~36. Windows 40 border on the annular groove
30, so that upon removal of tear-off strip portion 34, as will be described
below, windows 40 turn into downwardly disposed V-shaped, weakened
areas on either side of the locking flange segments 36. The part of skirt or
upper portion 32 located between windows 40 that contains locking flange
so segments 36 thus becomes a flap 42 that can be pried outwardly and
upwardly to release the locking flange segments 36 from container upper
locking flange 1 ~ and thus allow for the easy removal of lid 10 from
.container 12. The thin membrane windows can tear as flaps 42 are pried
upwardly, or, if windows 40 are made thicker, they can stretch elastically and
act as springs to help return flaps 42 to the locking position. The membranes
of windows 40 typically are about .2 to .5 mm (0.00 to 0.020 inches) thick,
and prevent dirt or other foreign matter from entering windows 40 and
collecting on flange 20. If desired, membrane windows 40 can have
strengthening or reinforcing ribs 43, especially if it is desired that the
2 o membranes not tear upon the lifting of flaps 42. With ribs 43, flaps 42
will
more readily resume their original shape after being lifted.
Refernng next to Figure 7, a modified membrane window 45 is shown
where the membranes have openings 47 therethrough bordering on the
annular groove 30. The removal of tear-off strip portion 34 thus leaves
2 5 downwardly disposed open, inverted V-shaped open notches on either side of
the locking flange segments 36 to make the lifting of flaps 42 easier. The
openings or notches 47 can be any shape or configuration desired, even
narrow vertical slits, if it is desired to prevent dirt or debris from passing
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through,windows 45.
As seen best in Figure 4, tear-off strip portion 34 is formed with a
window 44 located adjacent to annular groove 30. Again, window 44 could
have a thin wall or membrane covering to keep dirt out, or it could be an
actual opening formed in tear-off strip portion 34. Tear-off strip portion 34
has a lower peripheral edge 46, and tear-off strip portion 34 is formed with a
reduced thickness portion 48 located between window 44 and lower
peripheral edge 46. To remove tear-off strip portion 34, orie can insert a
tool,
such a screwdriver into window 44 and pry the tear-off strip portion 34
outwardly to break reduced thickness portion 48. This provides a flap or tab
50 that can be grasped and pulled outwardly to tear the tear-off strip portion
34 along groove 30 to remove tear-off strip portion 34. It will be appreciated
that removal of tear-off strip 34 also removes the locking flange or flanges
38, leaving only the intermittent locking flange segments 36 to engage the
i5 container. This permits lid 10 to be removed easily by prying up flaps 42,
yet
the intermittent locking flange segment 36 permit lid 10 to be placed again on
container 12 with good sealing engagement between the container rim or
annular flange 26 and lid sealing groove 28. It will also be appreciated that
breaking reduced thickness portion 48, and perhaps window 44, is a tamper
2 o evidence feature for lid 10.
Referring to Figure 8, it will be seen that in this embodiment, lid 10 is
provided with 4 equally-spaced intermittent locking flange segments 36 on
the skirt upper portion 32. Also, tear-off strip portion 34 has an inwardly
disposed locking flange 3 8 that is a continuous annular flange located around
25 the inside of tear-off strip portion 34. Locking flange 38-passes over the
reduced thickness portion 48, and depending on the thickness of locking
flange 3 8, it may be necessary to insert a knife into window 44 and cut
downwardly through locking flange 38 and reduced thickness portion 48 in
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order to break out tab 50 in this embodiment.
In the embodiment shown iri Figure 9, there are only two diametrically
opposed locking flange segments 36 on the inside of skirt upper portion 32.
Also, tear-off strip portion 34 has a pair of semi-circular and inwardly
disposed locking flanges or flange segments 38 rather than a continuous
locking flange 38. The Figure 9 embodiment is useful for smaller containers
where the lids need not be held so securely on containers 12. The Figure 8
embodiment is useful for Larger containers where stronger retention between
the lid and the container is desired. In fact, locking flange segments 36
could
2 o be located between all of the pairs of openings 40 to make an even
stronger
connection between the lid and the container. It will be appreciated that the
size and the length and the number of locking flanges 36, and 38 can be
configured as desired to give the necessary shipping strength to the container
and Lid combination of the present invention, or to provide for easier or more
difficult removal and reinstallation of lid 10 for the re-use of container 12.
Shown in Figures 1 OA to I OC, are embodiments of the lid of the
invention in which the outer surface of the skirt upper portion 32
corresponding to the position of the intermittent locking flange segment 36
includes indicator means on the outer surface, indicating to the user where to
2 0 lift the flaps 42 when removing the lid 10 from the container, after the
tear-
off strip 34 has been removed. Shown in Figure 10A is an embodiment
including the features of the lid of Figure 9 and further including indicator
means comprises a recessed portion 52 which includes arrows pointing
upwardly 54. The recessed portion and arrows indicate to the user where the
intermittent locking flange 36 is located and thus where to lift the flap to
disengage the lid from the upper outwardly disposed flange 18 of the
container. Shown in Figure l OB and 1 OC are embodiments with variations in
the indicator means, namely in Figure l OB a pattern of protrusions 56 are
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present in the recessed portion 52 and in Figure 1 OC a high gloss patterned
surface 58 are present in the recessed portion, indicating the position of the
locking flange segments 36 and thereby where to lift the flaps 42. The
recessed portion 52 in any of these embodiments may have a matted or
textured surface. The thin membrane windows 40 of the embodiments shown
in Figures 10A to lOC may include strengthening ribs 43, such as those
shown in Figures 5 and 6. Such windows may be modified in the manner
shown in Figure 7.
It should be understood that the lid and container of the invention may
1o be rectangular or square in circumference. Examples of square lid
embodiments are shown in Figures 11 to 12. The square lids preferably
include the features as described in the embodiments above and illustrated in
the Figures herein and may be utilized in essentially the same manner. 'For
example shown in Figure 11 an embodiment of the lid 10 is provided with
four intermittent locking flange segments 36 on the skirt upper portion 32,
one on each side of the square for engaging the outwardly disposed locking
flange 18 of the container. A tear off strip portion 34 has an inwardly
disposed locking flange 38 present on each side of the square. This inwardly
disposed locking flange 3 8 may be interrupted at each corner 60 of the
2 o square. The tear off strip portion 34 includes a reduced thickness portion
48
with a window 44 created when tab 50 is engaged with the skirt upper portion
32. The locking flange 38 passes over the reduced thickness portion and
depending on the thickness of the flange, it may be necessary to cut through
the locking flange and reduced thickness portion in order to break out tab 50.
2 5 Figure 11 shows tab 50 broken out of engagement with the skirt upper
portion 32. In a certain variation of this embodiment, the locking flange 38
is
interrupted at the reduced thickness portion, thereby eliminating the need to
cut through the flange 38 and reduced thickness portion 48 with a foreign
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implement, allowing for easier removal of the tear off strip.
The embodiment of Figure 11 includes indicator means in the form of
a recessed portion SZ with arrows S4 on the skirt upper portion S4
corresponding to each intermittent locking flange 36 segment thereby
s indicating to the user where to lift the lid when disengaging it from the
container. The skirt upper portion is formed with thin membrane windows 40
on either side of the upper locking flange segments 36. As discussed above;
windows border on the annual groove 30 between the skirt upper portion 32
and tear off strip portion 34 such that upon removal of the tear off strip
z o portion 34 the windows become downwardly disposed V shaped weakened
areas, thereby allowing the upper flange segments 36 between the windows
40 to be more easily lifted and released from the container outwardly
disposed upper locking flange 18. The thin membrane windows on the
square shaped lid of the invention described and illustrated herein may have
15 the same features and as those windows and variations thereof as described
above and shown in the Figures, including but not limited to Figures 4, 5, 6
and 7.
In the second embodiment of the square container shown in Figure 12,
there are only twb locking flange segments 36 on the inside of skirt upper
2 0 portion 32, positioned on diametrically opposed sides of the square. This
embodiment includes a recessed portion S2 indicating where to lift the lid for
disengagement of the upper locking flange segment with the container upper
locking flange 18. The tear off strip portion 34 may include a locking flange
3 8 extending around the entirety of the lid. Alternately, as discussed above
2 5 and disclosed in the figures, the tear off strip portion 34 may have
several
discontinuous locking flange segments 3 8 extending around the lid. For
example, the corners 60 of the square may not include the flange segment 38.
The embodiment shown in Figure 12 may be utilized for containers
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where the lids need not be held so securely on containers 12. Since the
Figure 11 embodiment include greater means for retention of the lid on the
container due to the presence of upper locking flange segments 36 on each
side of the square container, the lid of Figure 11 will be useful for
containers
s where stronger retention between the lid and the container is desired.
As will be apparent to those skilled in the art in the light of the
foregoing disclosure, many alterations and modifications are possible in the
practice of this invention without departing from the spirit or scope thereof.
Accordingly, the scope of the invention is to be construed in accordance with
z o the substance defined by the following claims.
