Note: Descriptions are shown in the official language in which they were submitted.
*
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TAMPER INDIC~TING CLOSURE HAVING
RETAINING HOOP WITH RELIEF WINDOWS
This invention relates to container closures
of the type having a frangible tamper indicating band
which, when broken, provides a visible indication that
the container has been opened.
The Problem in the Art
Closures having tamper indicating bands
typically include some type of band retaining means
which engages the underside of a locking bead around
the neck of the container. When the closure is opened
for the first time, the "retainer" exerts a downward
force on the band w~iich causes the band to sever and
separate from the upper part of the closure. A
visible gap is thereupon opened between the band and
the upper part of the closure, which shows that the
container and/or closure has been at least partially
opened. The retainer is often in the form of spaced
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apart up-turned tabs or "fishhooks" around the inside
of the band.
In order to assure that the tamper indicat-
ing band breaks in the initial opening, it is of
course critical that the retainer positively engage
the locking bead on the container and be arrested by
it, rather than sliding upwardly past the bead as the
closure is removed. For this reason a relatively
stiff and unflexible retainer is desirable. If the
retainer is too pliable or flexible, it may collapse
or fold down when it comes into engagement with the
locking bead and thus not resist upward movement of
the band, and thereby permit the closure to be removed
without visibly affecting the tamper indicating band.
15, However, molding processes usually require that the
l retainer be molded in a "down" position, in which the
il retainer is angled inwardly and downwardly from the
top. If the retainer, molded in the down position, is
too stiff it resists being turned or folded from that
20initial "as molded" position, to its upturned, locking
bead-engaging, use position.
In some instances, a closure can be applied
to a container with the retainer in the down, as
molded position; the retainer is automatically turned
25up or inverted to the use position as the closure is
secured in place. In other cases, however, where the
retainer is stiffer so as better to resist inadvertent
downfolding on opening, a separate post-forming
~ :" . -"- - .~
092/03348 ~ 0~ r ~ ~ 8 PCT/US91/0~434
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operation is used to turn it up after the closure has
been molded but before the closure is applied to the
container. Two factors are at cross purposes: the
stiffer the retainer is, the more difficult it is to
invert frcm the down, as made, position to the up,
bead engaging, use position, but when in that position
the more securely it will engage the locking bead when
the closure is removed. If the retainer is so stiff
that it must be turned up by applying point force
progressively around its circumference at its inner
edge, the application of the large force required
usually slows the operation.
Thus there has been a need for a tamper-
indicating closure having a retaining means which can
be turned from a down, molded position, to an up, use
position, at a rate consistent with high production
speeds, but which is still stiff enough to insure that
the band will break upon opening.
Prior Art
Ostrowsky U.S. patent No. 4,478,343 in
Figure 10 shows a closure having a tamper indicating
band with retaining tabs that are separated by thin
webs between them. The webs extend inwardly nearly as
far as the tabs. Gaps are presented between spaced
apart hinged segments to make the hinge more flexible.
In that closure the tabs are circumferentially flexi-
ble and, when swung through a horizontal center
position, the inside dimension of the retainer is
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reduced by circumferential overlap along its inner
edge.
Kerr U.S. Patent No. 4,506,795 shows a
tamper evident closure having a large number of
individual tabs, each upwardly bent to engage the
underside of a bead on the container. The tabs are
separated from one another.
Hannon No. 4,592,475 shows another closure
having circumferentially spaced tabs.
Gregory et al No. 4,613,052 shows a tamper
indicating band which is generally cylindrical,
connected to the lower end of a tamper indicating band
by frangible bridges. The entire band is folded
inwardly to a bead-engaging position by a separate
post-forming operation, prior to application of the
cap to the container.
Hayes No. 4,657,153 shows a closure having a
plurality of spaced, upturned locking tabs for engag-
ing beneath the bead of a container. In Figure 7A of
that patent, hinges 13 at the base of tabs 10 are
separated by intermediate slots 14. Each window is
several times longer than the respective hinge.
Begley No. 4,796,770 shows a closure having
a retaining means in the form of a plurality of hinged
flaps which are separated circumferentially by notches
to function independently.
In Wright Reissue patent No. 32,879, sepa-
rately projecting stops are hinged along the lower
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edge of the tamper indicating band and are swung
upwardly and inwardly to project into and through
relief windows above the band which provide clearance
for the stops to be cammed outwardly when the cap is
applied.
Brief Summary of the Invention
If the retainer is in the form of a continu-
ous, inwardly angulated unapertured conical hoop below
the tamper indicating band, so-called "hoop strength"
generally makes it difficult to turn the retainer
inside out as is required to invert it from the down,
as molded position, to the up, bead-engaging position.
In accordance with this invention, the retainer is in
the form of a flap or hoop which is essentially
continuous around its distal (inner) edge. It is
hinged along its outer edge to the band, and has a
series of "relief windows" or internal deformation
areas spaced along it. (As used herein in reference
to the distal edge of the retainer, "essentially con-
tinuous" means that the retainer is unbroken or has
only a single gap in its distal edge. A break such as
a transverse gap in the distal edge makes it easier to
press the retainer over the locking bead of a con-
tainer, in comparison to the retainer of an otherwise
similar closure having an unbroken edge. It is
however far more difficult to remove a closure having
no split or only a single split than a closure with a
plurality of splits around its distal edge.)
W092/03348 2 q ~ 9 ~ PCT/US91/05434~--
The relief windows provide a balance between
the force required to position the closure on the
container, and the force required to provide the
indication of tampering. They permit the hinged
and/or distal edges of the retainer to deform in an
advantageous manner, under the compression which
arises during inversion. When the retainer is being
folded to its up position, it deforms to relieve
compression as it moves through a plane perpendicular
to the closure center axis. The deformation may be in
the plane of the retainer and away from the hinge line
at the lower edge of the band; or it may appear as an
arc which is perpendicular to the plane of the re
tainer; or the "mullions" between the windows may
buckle adjacent the hinge line in a direction trans
verse to the plane of the retainer.
The relief windows may be "open" windows,
that is, apertures or holes. Alternatively, it has
also been found that, rather than providing openings
through the hoop to relieve hoop strength, a similar
result can be achieved by providing relatively thin
webs rather than open windows. The webs must be thin
enough that, like open windows, they also will relieve
hoop strength. The webs, like open windows, are
within (bounded by) the hoop and do not extend to the
inner edge of the hoop. Like open windows, the
provision of thin relief webs enables the hoop to be
turned inside out much more easily, prior to the time
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the closure is secured to the container. The webs
relieve the hoop strength as the hoop is turned from
its down position, through an intermediate inturned
center position in which its inside edge is in com-
pression and its outside (hinge) edge is in tension,
to its up position, so that the hoop can more readily
be folded up for use, prior to seating on the con-
tainer. Therefore, as used herein, the unmodified
term l'windows" is intended to mean and include both
open windows and windows closed by a web so thin that
it acts like an open window during inversion of the
retainer.
The provision of a hoop with internal relief
areas is preferable to spaced discontinuous band
retaining means joined by webs, as taught by Ostrowsky
patent No. 4,478,343. That patent calls for tabs
connected by thin webs; the inner edges of the webs
are difficult to form consistently on a production
basis. The retainer of this invention can be con-
tinuous around the closure, that is, without "gaps"
along its inner edge. It can be relatively stiffer
than such separate tabs, and indeed can be thicker at
its inner (distal) edge than at its outer (hinge)
edge, which is desirable to provide a tighter "grip"
on the container.
Surprisingly, the windows afford a number of
unexpected advantages. In comparison to a retainer
without windows, they enable the retainer to be folded
W O 92/03348 2 0 8 9 ~ ~ 8 PC~r/US91/05434j
~- up more easily and quickly, prior to the time the
closure is secured to the container. The windows more
effectively relieve the compression stress as the
retainer is up turned from the down position. The
windows also provide a better balance between the
force required to secure the closure on the container
and the circumferential shearing force required to
provide ~he indication of tampering, by increasing the
shearing force. Preferably the windows have substan-
tial "height" in comparison to the height (transverse
dimension) of the retainer; optimally, they should
extend at least 1/3 of the distance from the lower
edge of the band (i.e., the hinge edge) to the distal
(inner) edge of the retainer.
The retainer of this invention can be rela-
tively stiff, and is preferably thicker at its inner
(distal) edge than at its outer (hinge) edge. If the
windows are narrow in relation to the circumferential
dimension of the hinges between them, then the re-
tainer (as viewed in plan in the use position) assumes
a distinctly polygonal shape in which the portions
inward of the hinges press more tightly against that
container neck than the portions inward of the win-
dows. This improves the "grip" of the retainer on the
container and hence improves the band severing action
when the closure is turned to open it.
A further advantage is that in use the
entire inner edge of the retainer engages or lies very
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_ g _ ,
'i close to the container neck; preferably there are no
significant gaps between the retainer edge and the
container wall.
Yet another advantage is that, if the
windows are relatively small in area, or are closed by
webs, they do not permit the entrance of an insect
into the space between the band and the container,
above the retainer. Indeed, even the size of open
windows as formed can be reduced when the retainer is
folded up, because the retainer deforms into the
window area. This makes possible compliance with
recommendations against any gap larger than .015" in
the closure.
Still further, the open relief windows act
as drain ports for wash water directed downwardly
through wash slots above and/or upwardly from a point
below the retainer. Wash water so directed can flow
over the container threads or lugs to wash them, and
then drain through open windows at the bottom of the
retainer.
Description of the Drawinqs
The structure which provides these advan-
tages can best be further described and understood by
reference to the accompanying drawings, in which:
Figure 1 is a perspective view of the top
part of a container having a closure in accordance
with a preferred form of this invention;
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Figure 2 (on a separate srheet from Figure 1)
is an enlarged axial cross-section taken on line 2-2
of Figure l;
Figure 2A is an enlarged sectional view
similar to Figure 2 but shows a closure having relief
windows in the form of thin webs, rather than aper-
tures;
Figure 3 is an enlarged fragmentary perspec-
tive view of the tamper-indicating band and retainer
of the closure of Figure 2, showing the retainer in
its down, as-formed position;
Figure 4 is a bottom plan view of the
closure showing the retainer in its as-formed posi-
tion;
Figure 5 is a bottom plan view similar to
Figure 4 but shows the retainer after it has been
folded to its up or use position, for engaging the
container locking bead;
Figure 6 is a fragmentary perspective view
similar to Figure 3 but shows the deformation of the
retainer after it has been folded to its use position;
Figure 7 is an enlarged fragmentary perspec-
tive view similar to Figure 3 but shows a closure
having a retainer with more and larger windows, in
accordance with a modified form of the invention;
Figure 7A is a view similar to Figure 7, but
is of a closure having relief windows in the form of
thin webs;
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Figure 8 is a bottom plan view of the
closure of Figure 7, with the retainer in its up
position;
Figure 9 is a view similar to Figures 3 and
7 but shows a closure having a retainer with still
larger windows, in accordance with another modified
form of the invention;
Figure 10 is a fragmentary perspective view
of the closure of Figure 9, with the retainer in its
up position;
Figure 11 is an enlarged fragmentary verti-
cal section diagrammatically illustrating a retainer
being inverted from the down to the up position; and
Figure 12 is a section similar to Figure 11
but shows the various ways in which the hoop may
deform upon inversion.
Detailed ~escription
In the drawings a container 10 is shown
having a closure 11 applied to its top opening. For
purposes of illustration closure 11 is shown as a
one-piece plastic molding having an integral top 12
and skirt 14. However, it is contemplated that the
principles of the invention are also useful with
composite closures in which a metal or composite disk
is inserted into an annular plastic shell. As used
herein, the term "top" in reference to the closure
includes b_th integral tops and separate tops; the
shell or skirt 14 may be integral with or separate
from the top.
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The container lO shown for purposes of
illustration has closure securing means in the form of
external threads 16 around its neck, which engage
internal threads 18 on the inside of the closure 11.
It should be appreciated, however, that the invention
is useful not only on threaded containers but also on
containers having interrupted canted lugs or a snap
bead.
Around the lower edge 20 of closure skirt 14
there is attached a frangible or severable tamper-
indicating band indicated generally by 22. This band
22 is in the form of an annulus and is formed in-
tegrally with closure skirt 14, to which it is con-
nected by a series of spaced frangible bridges 25 (see
Figure 3). The bridges 25 may be interruptions in a
circumferential score line or partial cut 27 around
the outside of the closure. The score line 27 severs
band 22 from the remainder of the closure except at
these bridges. Bridges 25 thus act as the "weak link"
along which the tamper-indicating band 22 severs or
tears from the upper part of the closure. (In the
embodiment shown, the band 22 separates entirely from
the rest of the closure when the bridges 25 rupture,
and remains on the container thereafter. It is
alternatively contemplated that band 22 may split
along a rupture line as indicated by dotted line in
Figure 7 and remain attached to the closure by a
flexible connector after the bridges 25 have been
~ ~ 092/03348 ~ 2 0 8 9 ~ ~ 8 PCT/US91/05434
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broken, so that the band is removed with the closure
rather than remaining on the container.)
As best shown in Figures 2 and 3, tamper-
indicating band 20 includes a band retaining means or
retainer 29 preferably in the form of a continuous
hoop or flap connected integrally along the lower edge
30 of band 22. (The flap may have a "split," gap, or
division as shown at 28 in Figure 4 in its inner or
distal edge 32 at one point around its circumference,
but this is not preferred.) Retainer 29 is molded in
a first position in which it is angulated downwardly
and inwardly from skirt 14 (see Fig. 3), i.e., away
from top 12. As best shown in Figure 2, the retainer
is preferably tapered so that it is thicker at its
inner edge 32 than at its hinge edge 35, to provide
greater stiffness.
Retainer 29 is hingedly connected to tamper-
indicating band 22 by a series of spaced flexible
integral hinges 34, each of which is preferably of
sufficient angular extent to act as an arcuate joint
when the retainer is folded about hinge edge 35, and
thereby provide an over-center hinging action. The
hinges 34 are separated or spaced from one another by
relief windows or deformation areas 36, as shown in
Figure 3. The windows 36 are preferably rectangular
with outer edges which are colinear with the hinges 34
along edge ~5. In the preferred embodiment shown, the
windows 36 have a substantial height (dimension in the
W092/03348 ~ ' 2 0 8 9 5 6 8 PCT/US91/05434 ~
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direction toward the distal edge): they extend at
least 1/3 of the distance from the hinge edge to the
distal edge, that is, the unapertured portion above
the windows is less than 2/3 the height of the flap.
However, in any case it is important that windows 36
do not extend to distal edge 32, that is, distal edge
32 is continuous and unbroken across both the windows
36 and the hinges, except possibly for a split as at
28. The windows 36 may be open apertures or they may
be thin webs (as shown at 36A in Figs. 2A and 7A).
Preferably they begin at the hinge line 35 and extend
toward distal edge 32. The closer the windows 36
extend to edge 32, i.e., the more nearly they sever
the retainer, the less the hoop strength. If the
windows 36 (open or webbed) are too large in a given
closure and material, the retainer 29 may be so weak
as to slide past a locking bead 40 and not sever the
band at the score line 27. If webs are provided, they
must be membrane- or film-like in thickness, e.g.,
about 0.010-.020", in comparison to the hoop which may
for example be about .025-.060" thick. The webs are
preferably coextensive with the upward face of hoop
29, as shown in Figure 2A, but could alternatively lie
on the other (lower) face. In this embodiment the
"mullions" 44 and hinges between the windows are
wider, in circumferential extent, than the windows;
depending Oll closure size, they may be substantially
wider (e.g., about 1.5-6x) than the windows 36. In
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this embodiment the circumferential width of the
windows 36 is preferably at least twice their height,
depending upon the diameter of the cap 11. As shown
in Figure 2, the distal edges of the windows may be
angulated downward to facilitate stripping from the
mold.
The closure shell can be molded; webs, if
used, are molded thinner than the retainer in which
they are presented. As shown in Figures 2 and 2A, the
inner edge of the windows 36 or webs 36A may slant
downwardly to facilitate removal of the closure from
the mold.
As already indicated, these windows 36
provide a surprising effect when the retainer 29 is
inverted from its as-formed position (Fig. 3) to the
use position shown in Figures 2 and 6, in which the
inner edge 32 is positioned to hold beneath the
locking band 40 of container 10. Because the re-
tainer 29 is formed as a truncated cone with a circu-
lar distal edge 32, it might be thought that after
folding to the use position of Figure 2, it would
resume a circular configuration, the two positions
being symmetrical about a plane through hinge line 35.
However, that does not occur. On the contrary, in use
position the retainer takes on a generally polygonal
shape, as seen in plan in Figure 5. The polygonal
shape is most pronounced in closures with relatively
few and small windows.
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More particularly, I have found that the
provision of the relief areas 36 permits the retainer
to deform and thereby relieve the compression that
arises along the distal edge 3 2 as the retainer is
inverted from the down position to the up position.
In the embodiment of Figure 2, the distal edge 32
deforms in the radial direction, forming arcs or peaks
42 extending outwardly (perpendicularly to the plane
of the retainer) in the regions across the windows
(between the hinges). When the retainer 29 has been
folded to the up position of Figure 2, it surprisingly
assumes the generally polygonal configuration shown in
Figure 5, rather than a circular shape; the portions
of the retainer between the hinges (i.e., across the
windows 36) deform radially outwardly and thereby
reduce the distance between the band and the retainer
distal edge 32, with the hinge areas or mullions 44
between the windows 36 lying closer to the center axis
of the closure. This shape enables the retainer 29
better to grip the container sidewall beneath locking
band 40, regardless of manufacturing tolerances in the
dimensions of the container lO and the closure 11, and
more certa nly to shear the bridges 25 and cause the
tamper-indicating band to separate.
Because the retainer 29 normally conforms
relatively tightly to the container around its entire
periphery, it acts as a seal against insect infesta-
tion. The fit can be so close that no opening between
~ ~ 092/03348 2 0 8 9 S 6 8 PCT/US9l/05434
the distal edge 32 of the retainer and the container
wall exceeds the maximum recommended limit of .015".
The windows 36 themselves, if open areas, are par-
tially closed by the deformation of the retainer 29,
and the gap above them may itself be less than .015".
(Webs close the windows altogether.) Moreover, the
distance from the line of contact of retainer distal
edge 32 with the container, to the bottom 34 of the
closure, may be 1/8" or less, in compliance with
federal FSIS regulations. This avoids possible intake
of dirt or contamination into the container when the
vacuum is broken.
Apart from relieving hoop strength as the
retainer is inverted to the use position, open aper-
tures also facilitate water washing of the interthread
space between the closure 11 and the container lo.
For example, a water wash spray directed downwardly
through water slots above it in the closure 11, and/or
upwardly toward distal edge 32, can flow between the
lugs or interrupted threads to wash them, then drain
downwardly into the V-shaped pocket 48 carrying any
entrained food particles and flow out through the
windows 36.
In the embodiment shown in Figures 1-6 and
described above, the windows 36 are relatively few and
narrow in relation to the width of the hinge mullions
44 between them. As already noted, that embodiment
provides a relatively stiff retainer. For some
W O 92/03348 f 2n89568~ ' PC~r/US91/05434 ~
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applications so much stiffness is not needed and the
proportion of window area can be larger. This also
reduces the area of the pockets 48 between the re-
tainer and the band and provides a larger open area
for better water washing and drainage. Two embodi-
ments having progressively larger windows are shown
respectively in Figures 7 and 8, and 9 and lO.
In the embodiment of Figures 7 and 8, the
windows 36 are about equal in width (circumferential
dimension) to the hinge mullions 44 between them. In
this embodiment, as in the first, the areas above the
windows 36 deform outwardly radially toward band 22,
as indicated by arrow 45 in Figs. 6 and 12, but the
deformation of each is less because there are more
windows. In the up position, the retainer still forms
a polygon but the peaks 4 2 are much less pronounced
(see Fig. 8). They can for example be felt as non-
uniformities by running a finger around the inner edge
of the hoop 29 in the up position.
If the windows 36 are of still greater width
and/or height, i.e., wider than the hinges, as in the
embodiment of Figures 9 and lO, the retainer 29 still
distorts along its inner edge, across the windows, to
relieve compression stress, but in a different way.
Here the distortion is in a different direction than
the transverse distortion shown in Figures 6 and 8,
and is in the plane of the original (underformed)
band. In this embodiment the deformation is away from
~ ~ 092/03~8 ~ ~ 2 Q ~9 ~ :6~ ~ PCT/USg l/OS434
the hinge edge 35; as indicated by arrow 55 it is
parallel to mullions 44, rather than radial, and
distal edge 32 assumes a "wavy," undulating or up and
down configuration (see Figure 10). In this embodi-
ment the circumferentially narrow hinges may no longer
function as arcuate hinges; they bend along essen-
tially straight short lines, not arcs. This con-
figuration is useful for small diameter closures;
moreover, the wavy edge may interfit with correspond-
ing ribs formed on the container finish to insure
quicker band breakage upon turning. The windows
should be open for this type of deformation to occur;
webs would restrict it.
The various types of retainer deformation
are further illustrated in Figures 11 and 12. In the
down position, the inside diameter of the retainer,
measured at its innermost edge, is designated by 50.
In the up position (phantom line 52), it has approxi-
mately the same inside diameter 50. As the retainer
29 moves through the over-center (horizontal) posi-
tion, half way between the down and up positions, its
inside diameter wants to remain the same, but the
retainer must deform for this to be possible thereby
placing distal edge 32 in compression. Depending on
relative window size and other factors, the distal
edge will deform upwardly and inwardly in the plane of
retainer 29 as at 54, or perpendicular to its plane,
as at 42; or the hinge mullions can buckle from the
2089~68
W092/03348 - PCT/US91/OS434
-20-
plane, as at 58 in Figure 12. In each case the
deformation is transverse to the original (undeformed)
arcs of edges 32 and 35. The deformation occurs as
the retainer crosses center but tends to remain after
the retainer has reached the up position. In each
case the accommodation of compression stress enables
the retainer to be inverted from down to up by apply-
ing direct axial force simultaneously around the
entire distal edge. The retainer need not be turned
up by applying spot force progressively around the
edge to "roll up" the retainer. This saves substan-
tial time on a production line.
Having described the invention, what is
claimed is:
