Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION OF THE PRIOR ~RT
Various types of cap constructions utilizing liners
have been devised in the past. These liners are employed to
- seal the contents of the container preventing leaking between
the threaded portions of a container neck and the cap by
providing for a positive seal at the mouth of the container.
Such previous cap constructions and liners and material used
for liners therefor have been a compromise between -the require-
ment that the liner material be stress and crack resistant
while also being moisture impervious and impervious to chemicals
and acids, yet being bendable and compressible enough to provide
for an effective seal. The present invention overcomes the
difficulties of the prior art liner material and has all of
the advantages of these prior materials without the corresponding
disadvantages. A further advantage of the liner according to
the present invention is that liners are capable of being
stamped out of stock liner material without freezing.
SUMMARY OF THE INVENTION
One of the features of the invention resides in liner
material capable of forming a liner that is freely rotatable
within the cap until such time as the mouth of the container is
firmly against the liner compressing the liner so that an
intermediate layer of the liner is compressed and expands
outwardly thereby abuttingly against the side walls
of the cap for making a most effective seal.
A further object of the invention resides in the
production of a liner material that is capable of being extruded
as a multi-layer sandwich.
Still further, objects and features of this invention
resides in the provision of a cap and liner therefor that is
capable of being extruded by conventional machinery and which
can be conveniently stamped to shape without requiring freezing
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thereby permitting manufacture at a relatively low cost, and
which is highly effective in use.
These objects are attained by the invention which
contemplates a closure device which comprises a cap having a
top and an internally threaded cylindrical side wall with the
side wall having a groove therein adjacent the top, and a
liner normally rotatably disposed in the groove and including
a disc having one outer layer and another layer and bonded
thereto. The outer layer is relatively thin and non-resilient,
with the another layer being relatively thick, and being resil-
ient, and being compressible to form a lip extending beyond
the periphery of the outer layer and into engagement with the
side wall in the groove. Another layer being relatively thick.
These, together with the various ancillary objects
and features of this invention, which will become apparent as
the following description proceeds, are attained by this liner
material, a preferred embodiment of which is illustrated in the
accompanying drawing, by way of example only, wherein:
BRIEF DESCRIPTION OF THE DRAWING
Fig. 1 is an exploded sectional detail view illus-
trating the cap and liner therefor made from liner material
according to the invention;
Fig. 2 is a sectional detail view showing the cap
liner therefor in a stage of being secured on the neck of
a container;
Fig. 3 is an enlarged vertical detail view illus-
trating a portion of the cap and liner therefor as firmly
secured on a container;
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Fig. 4 is a partial sectional view of the liner
material;
Fig. 5 is a view similar to Fig. 4 but showing the
shape of the liner after ït has been compressed when the cap has
been tightly closed on the container;
Fig. 6 is a sectional view of a modification; and
Fig. 7 is a sectional detail view of a modified form
of liner material.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
With continuing reference to the accompanying drawing,
wherein like reference numerals designate similar parts throughout
the various views, reference numeral 10 is used to generally
designate a conventional container such as a bottle, tube, or
can having a neck 12 which is threaded at 14. In order to pro-
vide a closure for the container 10 a cap 16 is employed which
includes cylindrical side walls 18 which are internally threaded
at 20 and a top 22. A cylindrical groove 24 is formed as the
uppermost of the threads 20 and is for the purpose of receiving
therein a liner 26. The cap 16 is preferably molded out of any
suitable synthetic plastic material and is adapted to be thread-
edly secured on the neck 12 with the threads 20 engaging the
threads 14.
The liner 26, see Fig. 4, is from a liner material
in accordance with the invention formed of a sandwich of outer
layers 28, and 30, and an innerlayer 32, the liner 26 preferably
being stamped in the shape of a disc. The outer layers 28 and
30 are formed of a low density polyethylene, such as that sold
under the trademark "Alathion 20". This material is stress
resistant, crack resistant, relatively non-resilient, impervious
and is extruded in a very thin layer in the order of approximately
--4--
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1-1/2 one-thousandths of an inch. The inbermediate layer 32 is
a thermoplastic rubber-like material such as butylene in poly-
ethylene known as pliotheme, or other resilient material such
as ethylene vinyl acetate or the material sold under the trade-
mark sraton, which is a thermoplastic rubber. Particularly,
this material is resilient though not necessarily as resistant
to stress and cracks/or as impervious to foreign substances as
the material of the outer layers 28 and 30. When the sandwich
is manufactured by way of simultaneous multiple extrusionj the
outer layers 28 and 30 are extruded at a temperature approximate-
ly 300 to 400F while the intermediate layer 32 is extruded at
approximately 220F to 320F. The various layers are brought
together within a combination dye and at about 300F for bending
within the combination dye. The resultant sheet material has
a much increased resistance to distortion or stress, can be
stamped without freezing and is impervious to chemicals and
acids as well as moisture.
When the disc 26 is inserted in the groove 24 in a
normal state it will freely rotàte therein permitting for
effective setting of the disc 26 within the groove 24 and
effective engagement of the mouth 15 of the container 10 against
the under surface 34 of the layer 30. Continued closure of the
cap 16 will cause the resilient intermediate layer 32 to be
compressed exuding a tongue 36 beyond the peripheral edges of
the outer layers 28 and 30 and as shown in Fig. 3 against the
inner wall of the groove 24 frictionally sealing the liner 26
with the cap 16. Thus, there is achieved an inner effective
seal and closure for the contents of the container 10 than
heretofore possible to achieve while retaining all of the desir-
able features of the nonresilient low density polyethylene which
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is used for the outer layers, and which are relatively thin soas to permit for an effectively resilient liner.
It has been found that for the liner material accord-
ing to the invention it is desirable that the intermediate layer
32 be between 12 to 30 times the normal width of each of the
outer layers 28 and 30.
In Figs. 6 and 7 there is shown a modified form of
the invention wherein a two-ply liner is used. The cap has its
top 122 serve as the upper outer liner, there being only an
intermediate liner 132 and a lower outer liner 130.
In connection with the two-ply liner, it has been
found that the intermediate layer may be made of a foamed poly-
ethylene and may be from 12 to 40 times the thickness of the
outer layer. The use of foamed polyethylene results in a savings
of material. The foamed polyethylene may be bonded by any suit-
able adhesive to the undersurface of the top of the cap as
desired.
A latitude of modification, substitution and change
is intended in the foregoing disclosure, and in some instances
some features of the invention will be employed without a
corresponding use of other features.
