Note: Descriptions are shown in the official language in which they were submitted.
BACKGROUND OF THE INVENTION
The present inventi~n relates to improvements in con- !
~i tainer closures and more specifically to a one~piece plastic
i closure having integral sealing means engageable with the co~-
! tainer finish to seal the container contents~ These closure
j~ caps are commonly referred ~o as ~linerless closures~.
l~l Linerless closures are not new per se and generally
ill consis~ of a top and a depending skirt having internal screw
!1~ threads which engage with complementary threads on the neck of
, a container for applying and removing the cap and sealing mean~
I depending from the top and engageable with the container in~.sh.
~ The sealing means ;n these prior linerless closures generaL~
¦¦ consists of one or more seali~g rings or flanges which depend
from the inside surface of the top and eDgage the finish or end
~ surface defining the disch~arge opening in th~ neck of a con-
; 1¦ tainer such as a bottle.ii Typical oi closure assembl~es of ~hi3 ~ype are those
¦ shown in the following U. S. patents: J.A. Mclntosh, No. 3~286, ~:~
Il 866, R. H. Gibson~ ~. 3,2.32,470, J. W..Wandellg No. 3,053,40~
!¦ and W. J. Marks, No. 3,815,771. In each of these paten~s there
il is shown a one-piece closure of generally c~p-like shape having
I, a series of sealing rings depending from the inside ~ur~ace o~
.',, . I
,i .
.
. .
.
the top of the cap adapted to engage the flnish or axial e~ld
face of the container when the cap is applied thereto. The
containers are usually made of glass by a conventional process.
It has been observed that surface irregularities in the form of
depressions or undulations in the finish of ~he glass are ~uite
common, particularly in the surface of the a~ial end face of the
container as illustrated in McIntosh, No. 3,286,866 Other
common imperfections include small projections or pips and
small pock-like openings. It can readily be appreciated ~a~ ¦
îf the sealing rings confront a depression or enga8e a pro- ¦
jection directly~ there is the likelihood of a leakage path
which may produce actual leakage of product if large enough
and the container is not in an upright position as is sometlmes
the case during shipment and storage. In the case of an easily
vapori~ed product, there is loss even when the containe~ is
resting on its base Accordingly, it can be seen that es~e~ ¦
tia`lly single zone sealing as in McIntosh or the doubl~ zo~ ¦
seal of the other r~ferences may not be effective to block the
potentia`l leakage paths crea~ed by imperfections o tha type
noted above. Furthermore, it has been observed that a.relative !
ly rigid wall section of the cap characteristic of some of the
caps in Marks, No. 3~815,771~ does not conform to surface imp~r--;
fections a readily as a flexible resilient flange or rib.
Ihus~ the present inven~ion is designed to provide a sealing
_3_ .
~ z~
arrangement consisting of a pl-urality of resilien~ f~ex1ble
'; elements which engage the con~a~ner at a plurality of zones
, including the inner and outer rlm of ~he container and at points
,1 between the rims which combined define a series of baxriers
! blocking leakage ~-~ectively.
Accordingly, the present invention provides an
! in~proved linerless closure capable of effectively sealing
I~ highly evaporizable products by providing a seal which
Il minimizes product loss and which nevertheless is easily
removed even after the sealed container has been stored
, a substantial period of time.
,1 Also the present invention provides an improved
linerless closure which may be economically produced by
---- r
l1 a conventional molding process.
'. i, ~.
I I ~
ii SUMMARY OF THE INVENTION ¦
il Th2 above and o~her objects of the invention are
¦1, achieved by provision of a closure having a top and a depending j
'` sk~rt and means on the interior of the skirt for secur-Lng the
closure in place on a container. The locking means may comprise¦
1 complementary screw threads on the interior of the skirt anc~ the~ r~
i' neck of a container such as a conventional bottle, In the I i
,,
`~
Il -4- '
'`~' i 'l ,
.
present instance the closure cap includes sealing means in the
~ orm o~ a series of radially spaced, circumferentially extend-
jj ing flexible flanges and ribs depending from the inside top o~
the closure which are of varying axial height and which when
I the closure is in a seated or locked position provide a four
j zone contact at critical sealing areas of the container.
~ .ore specifically there is provided a closure made
of a plastic material comprising a top, a skirt depending from
the top, and means on the skirt for securing the closure over
the discharge opening in a container and the container finish
at the discharge end of said container, the improvement com-
prising sealing means formed integrally with the closure
and depending from the inside surface of the top consisting
of a pair of inner and outer circumferentially extending rela-
tively flexible flanges projecting axially from the top a
predetermined depth, each of said flanges having a sealing face
disposed angularly relative to the top adapted to engage the
container finish at radially spaced inner and outer zones, at
least a pair of radially spaced, circumferentially extending
~0 ribs intermediate said flanges projecting axially from the top
a depth less than that of the flanges and having a sealing face
engageable with the finish at a zone intermediate said inner
and outer zones.
-5-
.2~GBS
~1
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and features of the invention
will be more readily understood from a consideration of the
jl following detailed description, ~aken in connec~i.on with th~
1~ accompanying drawin~s, in wllich:
~j Fig. 1 is a side elevational view of a closure in
¦ accordance wlth the present invention applied to a cOTItainer;
Il Fig. 2 is a fragmentary sectional view of the linerless
j, closure;
10 ¦I Fig. 3 is a sectional view taken on lines 3-3 of Fig, 1
showing thè position oE the sealing means engaging the finish
on thé container ~/hen t~le closure cap is ful.ly seated;
Fig. 4 is an enlarged fraglllentary sectional vie~ showi.n~
the angular disposition of sealing flanges and ribs of the
, closure cap;
Il Fig. 5 is a sectional vJ.ew of t-l-e container closure
1~ axsemhly of Fig. 3 showing the closure as initially applied
Il to the container;
IlZ . '
! `
I,
-5a-
`: :
,, I
,I Fig. 6 is a sectional view of a container closure asseTn~
bly in accordance with the presen~ invention with the closure
¦ shown in a sealed or seated position; and
Fig. 7 is a sectional view of the container closure
assembly o~ Fig. 6 showing the closure as initially applied
~, to the container.
'I DESCRIPTION OF SPECIFIC EMBODIMENTS
There is illustrated in Figs. 1 and 3 a closure cap 10
in ac~ordance with the present invention adap~ed to be applled
over the discharge opening 12 in a container 14. The closure
Il cap 10 is o~ cup-like form including a generally disc-like top
¦l 16 having a skirt 18 depending rom its outer periphery. ~.on- ¦
~ ventional screw threads 20 are formed on the inner periphery of ¦
`~l the skirt which cooperate with a conventianal screw thread 2~ ¦
! on the exterior wall of the neck 24 of the container to permit
~,¦ application and removal of the cap 1~ simply by rotating th~
cap 1~ relative to the container 14. The skirt 18 includes a
series o~ smaIl longitudinally extending circumerentially
¦¦ spa~ed ribs or knurls 26 facilitating gripping during applica-
¦ ~on and removal of the cap 10. The cap is adapted to.be ~
¦I molded by conventional process of a semi-rigid plastic material,
¦ such as polypropylene. The container as illastrated is made of
glass, but may also be made of other materials.
In the present instance the cap 10 includes sealing
¦I means broadly designated by the numeral 32 which in the seated
or locked position engage the finish 34 of the container. In
6~
~ 6 ~ ~
the prese~t instance ~hb ~inish comprises a flat radial wall
section 34a and an ~nwardly and downwardly converging frustQ-
conical wall section 34b. The wall section 34b 13 preerably
convergent at an angle of abou~ 45 ralative to ~he p~a~e of
the radial wall sec~ion 34a. The sealing means comprises a
series o~ radially spaced, circumeren~ially extending sealin~
flanges and ribs depending from the inner ~ace o~ the top of
the ~losure and spaced radially inwardly ~om the sid~ wal~
~o that they enga~e and seal wi~h ~h~ container fini~ e
1~ ~eated or locked p~sitlon in the manner illustxa~ed in Fig. 3.
In the illustra~ed embodiment o~ ~he invention~ ~h~ series
includes ~nnex and oute~ sealing 1anges 36 a~ 38 o~ gener-
ally triangular cro~ section and of a predetermined axial
pro~ectlon or depth ~1 and a pair of intermediate sealing
ribs 40 and 42 of a shortex axial depth H~ than ~he inner and
outer ~lange~ 36, 38. Each o the 1anges and xibs has a seal-
ing ace which engages the container finish in the seated
position at four spaced zones, an inner zone Zl at the wall
sect~on 34b, an outer zone Z2 at the oute~ xim 46 and inter-
mediate zones Z3 and 24 at ~he wall section 34a. Tests, dis-
cussed below, have demonstrated that the improved and sim-
pliied one-pieee line~less closure provides an ef~ective
seal with a markedl~ reduced evapora~ion loss when used on
containexs for li~uid products. Tests also demonstrate
that removal torques are in a range permitting easy removal
of the cap even a~ter a significant storage pexiod. It will
be observed ~urther that the removal torque remains uniorm
even a~ter a signi~icant storage period providing uxther
evidence of seal integrity.
'I~ is believed that the speoific con~ ration o~ the
sealing ~la~ges and ribs and disposition ~elative to the con-
tainer ~inish are impor~ant factors in providing ~he improved
.
~.2~
sealing characteristics of the closure of the pxesent invention.
Thus, the inner sealing flange 36 which projects generally in
an axial direction from the top has a circumferential inner
wall 36a, generally perpen~icular to the top, a frusto-conical
sealing face 36d, which diverges downwardly and inwardly from
the top to a feathered edge or tip 36c. The sealing face 36b
is preferably disposed at an angle of about 25 to the trace
of the inner wall 36a or about 65 relative to inner surface
16a of the top. This shape provides the rib with a degree of
rigidity at its base adjacent the top and a degree of flexibil-
ity at its point of contact with the chamferred wall section
34b of the container finish. The outer sealing flange 38 like-
wise has a circumferential outer wall 38a extending generally
perpendicular to the top and a downwardly and ~utwardlydiver~-
ing frusto-conical sealing face 38b which terminates in a
feathered edge or tip 38c. Preferably the an~le of taper of
the sealing face 38b is about 20 relative to the trace of the
outer wall 38a or about 70 relative to the inside surface 16a
of the top. The axial depth Hl of the ~langes f~om the base
to the tip is preferably about 0.053 inchesO
The central sealing elements comprise a pair of circum-
ferentially extending, axially directed ribs 40, 42 depending
from inside surface 16a of the top and located between the
inner and outer sealing flanges 36 and 33. The sealing ribs
40 and 42 are of a generally triangular cross section and have
inner and outer circumferential walls 40a, 42a confronting
angularly oriented sealing faces 40b, 42b which merge with the
circumferential walls in edges or tips 40c, 42c. The sealing
faces 40b, 42b are disposed at an angle of approximately 60
relative to one another and as illustrated, each sealing face
40b, 42b projects at an angle o~ about 60 relative to the top
surface 16a. The ribs 40, 42 depend from the top an axial
- 8 -
B5
depth H~ approximately hal~ of the projection of the flanges or
about 0.030 inches. The inner wall 40a of the inner rib 40 is
preferably disposed at an angle of about 10 relative to a
circumferential surface of revolution Rl through the apex at
the base of the flange 36 and rib 40 and perpendicular to the
inside surface 16a of the top or about ~0 relative to surface
16a and describes an angle of approximately 35 relative to
the sealing face 36b of the inner flange 36. The outer cir-
cumferential wall 42a of the outer sealing llb 42 is preferably
perpendicular to the top surface 16a, and is therefore disposed
at an angle of about 20 relative to the sealing face 38b of
the outer flange 38.
In order to provide the sealing relationship shown in
Fig. 3 with a container having a chamferred finish of the type
illustrated when the cap is initially applied (Fig. 5), the
tip or edge 38c of the outer flange 38 is preferably disposed
slightly outboard of the cylindrical trace 46a of the outer
sidewall 46 of the neck of the container and the inner flange
36 is preferably disposed so that the tip 36c is aligned in-
~0 board of the juncture 47 of the axial and tapered wall sec-tions
34a, 34b of the container. In other words, the diameter D
of the outer flange 38 at the edge 38c is slightly greater
than the diameter D2 f the outer side wall 46 of the neck of
the container adjacent the outer rim 46 and the diameter D3
of the inner flange 36 at the edge 36c is less than the diam-
eter of the circular juncture 47 of the axial and tapered wall
sections 34a, 34b. It is noted that the diameter D3 is greater
than the diameter D5 of the inner side wall of the neck of the
container. By this arrangement, as the cap is threaded onto
the container, the outer sealing flange 38 is deflected slight-
ly outwardly so that its sealing face 38b engages the rounded
outer edge 46 of the container at the zone Z2 and the sealing
_ 9 _
face 36b of the inner flange 36 engages the tapered wall sec-
tion 34b at a point slightly below the juncture 47 of the
axial wall portion and tapered wall sections at the zone Z
The sealing faces 40b, 42b of the ribs 40 and 42 deflect away
., .
I from one another in the manner illus-trated to provide circum-
i' ferentially extending radially spaced seal cvntacts along the
, top face of the axial wall portion 34a at zones Z3 and Z4.
, Figs, 6 and~7 illustrate a modi~ied form o~ container
. finish for a linerless closure in accordance with the pr~sent
,l invention. The closure cap is identical to that described above
' and accordingly, the same reference mlmeral.s are used to iden-
~,', ti~y parts thereof, In this embodiment, however, the finish iO '~
l., of the container 51 comprises a radi.ally disposed axial end
`~' surface 52 having inner and outer rims S4, 56 defined by
., rounded corners mergi.ng with the inner ar~(l outer ~.,idewal.ls
~i 58, 60 of the neck of the container, The closure cap in this
instance is designed so that in the relaxed state prior to
!1 3ppl, cation of the closure to the container and hefore seating
i' thereof în the sealing position, the edge or tip 38c of the
,~, u~ flange is located slightly outboard o~ ~he outer sidew~li j
~1 oO of the container neck and the edge or tip 36c of the inner
i ~lange aligns approximately at the mid point o~ the axial sur-
li ~ace 52 of the con~ainer finish, In other words, the diameter
!, Dl of the outer flange 38 at the edge 38c is slightly greater
i` than the diameter D2' of the outer side~1all of the neck of the
.. container adjacent the outer r;m 56 and the ~iameter D3
of tne inner flange 36 at the edge 36c is greater than the
diameter D4' oi the inner sidewall 58 of tlle neck and, as
Il ~
"
,
$~35
as illustrated, less than the diameter Dl. sy this arrangement 9
when the cap is rotated to a closed or sealed position, the
I sealing face 38b of the outer flange 38 engages at approximately
ii it~ mid point, the outer rim 56. The ribs 40 and 42 in this
.; .
instance engage the surface 52 of the container finish at
. radially spaced zones Z3 and Z4 and the inner flange is de-
il flected to almost a radial attitude providing a relatively wide
, inner sealing zone Zl adjacen~ the irner rim 5
Tests were conducted to determine product loss by
' evaporation in container closure assemblies in accordance with
il the present invention and also to evaluate removal torque, In
1'
,l typical tests, quart containers were illed with 86% prool
'l ethanol (43% by volume) and sealed with a 28 mm closure5 the
container finish and closure being o the type shown in Fig~
i !
a.ld 5. The closures were applied by autornati.c cappl.ng equip-
l, ment set ~or an application torque of approxi.mately 2S in.-l.b~.
i, ~h~ container-closure assemblies were initially weighed and
then placed on their sides in an oven ~set at 110F for a test
period o~ 21 days, At periodic intervals~ e.g , 7 and 14 days,
the containers were removed from the oven, placed in ambience fo
16 hours and weighed. In a significant number of the samples
. tested, there was zerv or substantially no evaporation loss and
the average was sig~ificantly below the liuqor industry standard
,; o~ .5 grams. The average removal torque remained substantially
i;
-lZ-
., I
constant in a range of about 13.2 in.-lbs. for the entire time
span of the tests for closures tested and were in a range
between 12-15 in.~lbs. These torque levels were within accept-
able limits. Uniformity i5, of course, desirable since it is
indicative of seal integrity and also insures that the closures
can be removed with compara~ive ease even after su~stantial
storage periods. Similar tests were conducted with container-
closure assemblies of the type shown in Figs. 6 and 7 and the
results were within the ranges discussed above. Thus, while
the invention has been described with particular reference to
specific embodiments thereof, it will be understood that it
may be embodied in a variety of forms diverse from those
specifically shown and described, without departing from the
spirit and scope of the invention as defined by the appended
claims.
~0
- 13
