Note: Descriptions are shown in the official language in which they were submitted.
WO 94/02372 !~'..'~~'~~6 PCT/US93/06301
VENTING AND DISPENSING CAP FOR A CONTAINER
Technical field
The present invention relates to a cap for a container for
containing liquids. The cap according to the invention
allows for the venting of the container as well as the
dispensing of said liquid.
Backcrround of the invention
Containers for containing liquids have been extensively
described in the art as well as their numerous possible
applications. In particular, many inventions have been
made relating to containers for containing liquids which
generate pressure, such as bleach-containing compositions.
Indeed, specific problems are associated with such liquids,
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in that the pressure which builds up inside a closed
container containing such a liquid may raise safety issues,
or lead to the deformation of the container.
In the art, solutions to this problem have been proposed,
for instance by designing containers of specific shapes,
whereby the container has optimal resistance to pressure
build-up, limiting the degree of deformation. This type of
solution has the drawback that it limits the flexibility of
shape, material selection and material thickness when
designing such containers.
Other solutions relate to various venting caps for such
containers, which allow the gas generated inside the
container to escape. Such caps have been described for
instance in GB 2 032 892, where a cap is disclosed which
comprises a liner juxtaposed to the top of the cap which
allows for pressure relief via a thread in the side of the
cap. An improvement to this type of cap is known, where
the top of the cap further comprises recesses, whereby the
liner flexes into said recess as the pressure inside the
container builds up. The flexed liner allows for improved
pressure relief over the caps in GB 2 032 892 via the
recesses and the thread in the side of the cap.
However, said venting caps have the drawback that the cap
has to be removed from the container for the contained
liquid to be dispensed. It is thus an object of the
present invention to provide a cap which allows for the
venting of the container onto which said cap is affixed
without the leakage of the liquid contained in the
container, and which further allows for the dispensing of
said liquid, without said cap having to be removed from
said container.
Furthermore, the caps of the prior art are incompatible for
use with a container wherein the contained liquid is to be
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dispensed through a small opening such as a nozzle. It is
therefore another object of the present invention to
provide a venting and dispensing device which allows for
the dispensing of the contained liquid through a small
opening while ensuring appropriate venting.
Summary of the invention
Referring to Fig.l and Fig. 2 hereinafter, the present
invention is a cap for a container, said cap comprising an
interior and an exterior, said cap comprising a body (1)
and a closure (2), said body comprising a side wall (3) and
an adjoining top (4), wherein said side wall comprises
means (5) to let gases through to the ambient, wherein said
top comprises at least one recess (6) on the interior,
wherein said body further comprises a liner (7) juxtaposed
to said interior of said top, characterized in that said
top and said liner are pierced by a hole (8), and that said
body further comprises a tubular part (9) extending through
the hole in said top and said liner, said tubular part
having an exterior diameter corresponding to the diameter
of said hole, and wherein a sealing means maintains said
liner pressed against said interior of said top in a leak-
tight manner.
Detailed description of the invention
The cap according to the present invention comprises an
interior and an exterior. Unless otherwise specified, the
term "interior" hereinafter refers to what faces the
container onto which the cap is to be affixed. The term
exterior refers to what faces the ambient. Although not
limited thereto, the cap according to the present invention
is preferably made of any plastic material available to the
man skilled in the art. The cap according to the present
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invention comprises a body (1) and a closure (2). The body
of said cap comprises a side wall (3) and an adjoining top
(4) .
The side wall (3) of the body comes into contact with the
exterior of the neck of the container onto which the cap is
affixed. It is essential for the purpose of the present
invention that said side wall comprises means (5) to let
gases through to the ambient, thereby ensuring pressure
relief. The cap according to the present invention can be
permanently or removably affixed to the container by a
variety of means. Although it is an object of the present
invention to provide a cap which allows for dispensing of
the product without having to remove the cap from the
container, it is nevertheless desirable to have the
possibility to remove said cap from the container, for
instance when it is needed to dispense large amounts of
liquid, or to allow for the container to be ref filled.
Therefore, the cap may be screwed or snapped onto the
container. In a preferred embodiment of the present
invention, the cap is screwed onto the container, and'said
means (5) will therefore be in the form of a screw thread
on the interior of said side wall. In other possible
embodiments, said means (5) may consist of one or several
channels through said side wall (3), or along the interior
of said side wall.
An essential element of the cap according to the present
invention is that said top of said body comprises at least
one recess (6) on the interior. Said recess must be
shaped, dimensioned and situated in said face so as to
allow for the liner (7) described hereinafter to flex into
said recess so as to ensure pressure relief. In a
preferred embodiment of the invention, said recess is
located on the periphery of the interior of said top. In a
preferred embodiment of the invention, there are several
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recesses arranged at the periphery of the interior of said
top.
In a preferred embodiment of the present invention, the
interior of said top further comprises catches or a
protuberant ring, or any continuous protuberance (il) which
come into contact with the liner in a region of said liner
which is adjacent to the hole (8) so as to increase the
mechanical pressure exerted on the liner, thereby improving
the seal between said liner and the interior of said top.
Another essential element of the cap according to the
present invention is a liner (7) which is juxtaposed to the
interior of said top. Said liner must be impermeable to
the liquid contained in the container onto which the cap is
affixed, and said liner must be flexible so that it may
flex into the recesses in the interior of said top
described hereinabove, as the pressure builds up inside
said container. However, said liner must also be rigid
enough to seal the container making it liquid-tight even if
the closed container is inverted. In the cap according to
the present invention, said liner is juxtaposed to the
interior of said top. The selection of an appropriate
material for such liner will depend on the liquid to be
contained in the container, and thus will vary in each
instance. The critical factors to be met by said material
are impermeability and flexibility. Suitable liners for
use herein may be made from expanded polyethylene foam,
plastic mixtures including ethyl vinyl acetate (EVA), or
from rubbers including silicone rubbers.
Another essential element of the cap according to the
present invention is that said top of said body and said
liner are pierced with a hole (8) in order to allow for the
dispensing of the liquid contained in said container. It
is one of the advantages of the present invention that the
dimensions of said hole are not critical for the purpose of
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venting. Therefore one can choose the appropriate size for
said hole as a sole function of the end use envisioned for
the container, i.e. the desired dispensing characteristics.
For instance, one can choose to use a small opening such as
a nozzle in combination with a squeezable container in
order to be able to dispense the contained liquid as a jet.
According to the present invention said body further
comprises a tubular part (9) which extends through said
hole (8) in said top and said liner. The cross-section of
said tubular part may be circular, or alternatively, oval
in shape. Said tubular part allows for the liquid
contained in the container to be dispensed, and in a
preferred embodiment may be designed to provide an integral
sealing means to ensure that said liner is pressed against
the interior of said top in a leak-tight manner. The
tubular part may itself provide the dispensing system or it
may form a component of a more complex dispensing system,
such as a sprayer system. Said tubular part has an outside
smaller diameter corresponding to the diameter of said
hole.
According to the present invention, it is essential that
said tubular part be provided with a sealing means which
ensures that said liner is pressed against the interior of
said top in a leak-tight manner. The degree to which said
liner needs to be pressed against the interior of said top
depends mainly on physico-chemical properties of the liquid
contained in the container and the compressibility of the
liner material. In the absence of said sealing means, the
liquid contained in the container would leak through the
cap, between said liner and the interior of said top, along
the contours of said hole.
There are many possible variants to provide said sealing
means. The sealing means may be provided by appropriate
shaping and design of the tubular part, such that, when in
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position, the tubular part integrally provides the sealing
means. For instance, said tubular part may be provided
with catches or rings adjoining the outside of said tubular
part, both below said liner (hereinafter "lower" means) and
above the exterior of said top (hereinafter "upper" means)
which may hold said liner pressed against the interior of
said top in a leak-tight manner.
Alternatively, the sealing means may be provided as a
result of the physical process by which the tubular part is
inserted into the hole, and held fixed in place. For
example, said tubular part may be inserted by a hot-
stamping or heat-sealing process such that the liner is
fixed into position. The sealing means may also be
provided by a mechanical clamping means, which is non-
integral with the tubular part, such as a non-integral ring
part.
In a preferred embodiment, said tubular part is provided
with two rings (10), one below said liner and one above the
exterior of said top. Compared to the catches, the rings
have the advantage that they ensure an equal mechanical
pressure on said liner along the periphery of said tubular
part. Another advantage of using rings instead of catches
is that said rings can, in turn, be provided with catches
or protuberant rings or any continuous protuberances (12)
which come into contact with the liner in a region adjacent
to the hole, as hereinbefore described on the interior of
said top, so as to increase the mechanical pressure exerted
on the liner. Said lower and upper means may be of similar
or different sizes and shapes, e.g. it is possible to
combine catches and a ring in one embodiment, or to combine
two rings of different sizes. Said means may be
permanently or releasably fixed to said tubular part, or
both. For instance, a tubular part can be molded which
already comprises the lower means while the upper part of
said tubular part comprises a threading where the upper
PCT/US93/06301
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means e.g. a threaded ring can be screwed onto said upper
part of said tubular part, after said tubular part has been
assembled with said liner and said body.
In a preferred embodiment of the present invention, said
tubular part and said sealing means are integral, i.e. the
tubular part and the sealing means are provided as a single
piece, and said single piece is so dimensioned that it can
be snapped onto the preassembled liner and body. In this
preferred embodiment, it is advantageous to use lower and
upper means with different sizes so as to facilitate the
snap-on. In a preferred embodiment, the lower means is a
large ring and the upper means is a smaller, bevel-edged
ring, and the tubular part is snapped-on the preassembled
liner and body from underneath. This embodiment allows for
a fairly simple assembly of the cap while it provides a
tight seal between the liner and the body.
In a highly preferred embodiment of the present invention,
and referring to Fig. 2, said lower means are constituted
by a ring (13) which extends throughout the diameter of the
neck of the container onto which the cap is affixed. Said
ring also comprises perforations (14) so as to allow the
pressure through. The advantage of such a construction is
that it is said ring which forms a seal with the neck of
the container when the cap is screwed onto t'he container,
instead of the liner itself. Therefore, an equal
mechanical pressure is exerted on the whole surface of the
liner, and more importantly, a reproducible mechanical
pressure is exerted on the liner which is almost
independent from the torque generated as the cap is screwed
onto the container. Consequently, the liner cannot be
accidentally forced into the recesses on the interior of
the top as the cap is screwed too tightly, and the venting
characteristics of the cap are thus independent from said
torque. In order to further improve the seal between the
cap and the container, and in a further execution of this
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preferred embodiment, said ring comprises an adjoining side
wall (15) which extends along the interior of the neck of
the container.
The cap according to the present invention further
comprises a closure (2). A variety of closures are
available to the man skilled which are suitable for use
herein, provided said closures ensure a leak-tight closure
to the exterior opening of said tubular part (9). For
instance, closures can be used which are screwed or snapped
onto said body (1). As an alternative, closures can be
used which allow the dispensing of the contained liquid as
a spray. As further alternatives, said closure may be of
the flip top, turret cap or push-pull type.
