Note: Descriptions are shown in the official language in which they were submitted.
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INTEGRAL SELF-CLOSING DISPENSING CLOSURE FOR A TUBE
BACKGROUND OF THE INVENTION
This invention relates to a dispensing tube which has a
self-closing mem~rane at the exit orifice which is an integral
part of the shoulder of the tube. More particularly, this
invention relates to a dispensing tube where the shoulder and
membrane closure are molded in a single operation whereby the
membrane closure is an integral part of the shoulder.
The self-closing dispensing closures that are in use are
comprised of a pliable material which has at least one slit.
This type of a dispensing closure is very effective for use
with various viscous and paste-like materials. Such viscous
and paste-like materials include various food products,
dentifrices, lotions, shampoos and other personal care
products. In order to dispense such products from a
container, it is only necessary to apply a force onto the
product within the container so that it can be displaced from
the container. Since the only mode of displacement from the
container is through the slit opening, the product will be
delivered through the slit opening. Upon the release of the
force on the product in the container the pliable membrane of
the slit opening returns to its original position thereby
ceasing the dispensing of the product from the container. The
product remaining in the container is then retained in a
sealed condition. These closures can be effectively used on
pliable tubular containers.
Self-closing dispensing closures of this type are not
complicated and provide for a positive dispensing action.
Further, such self-closing dispensing closures are usually low
in cost in comparison to other types of closures and serve
very effectively to preserve the product which remains within
the contain~r. The slit opening in the closure will usually
be a single slit or a double slit which will usually intersect
at the center of each slit. A prime re~uirement with regard
to the material from which the closure is constructed is that
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the material have a memory with regard to its original
orientation. That is, the material must be of a type which
will return to its original orientation upon the cessation of
a pressure on the product which is being dispensed. It is
this memory which will cause the slit opening to close and to
thereby cut off the flow of product from the container.
Self-closing dispensing closures are usually constructed
of a number of pieces. In this construction, they effectively
dispense the contained product. There is also a good cut-off
of the product being dispensed when the pressure on the
product in the container is released. However, when an item
is made of two or more pieces that must be assembled, there is
the added cost of assembly. It is preferred that an item be
of one-piece construction. There is also the potential for
leakage. It has no~ been found that a self-closing dispensing
closure for a tubular container can be formed as a single item
integral with the shoulder for the tubular container. This
shoulder is then heat sealed onto the end of a tube to produce
the dispensing end of a tubular container.
Self-closing dispensing closures have been used for the
dispensing of paste-like products. In U.S. Patent 2,147,164
there is disclosed such a closure for use in a dispensing
collapsible tube container. The slitted membrane closure
which is disclosed in this patent consists of a rubber disk
which has a single slit therein. This slitted disk is held in
place by means of a flange on the upper part of the
collapsible dispensing tube. This slitted closure is then
further covered by means of a cap which is threadedly engaged
to the tube. While this is a useful structure for a tube
closure, it is rather complex and requires assembly. The
closure membrane is not an integral part of the shoulder of
the container.
U.S. Patent 2,552,715 discloses a pressure operated
dispensing nozzle for collapsible tubes. This dispensing
nozzle is fitted onto the top of the collapsible tube. It has
a slit opening for dispensing a paste-like product. The
paste-like product is dispensed via pressure which is applied
to the exterior of the collapsible tube. In this patent, the
membrane closure is not an integral part of the shoulder of
the container.
U.S. Patent 2,620,949 discloses another type of membrane
closure for collapsible tubes. In this closure, there is more
than a slit opening. There is as a part of the structure of
the cap, two side compartments and the walls of these
compartments for sealing off the closure when material is no
longer to be dispensed. This cap closure is crimped onto the
top of a collapsible tube and functions as its own support.
U.S. Patent 2,670,884 is directed to a self-sealing
membrane closure for a collapsible tube. This is an upwardly
extending shaped means. Further, in the area of the slit
opening, the closure is of an increased thickness. This
increased thickness is to ensure the closure of the slit
opening when a force is no longer applied on the tube and it
is intended to close dispensing product.
U.S. Patent 2,679,954 discloses a collapsible container
which has as the dispensing portion a membrane disk which has
a crossed slit opening. This crossed slit opening is in a
membrane disk which is maintained in place on the collapsible
tube by means of a threaded cap. The upper portion is open
over a significant part of its area to expose the membrane
disk. This provides for a positive containment of the disk
onto thP container.
U.S. Patent 2,802,607 discloses a domed shaped dispensing
cap for collapsible tubes. In this dispensing cap, there is a
slit opening on the top of the cap for the dispensing of the
contained product and a threaded portion on the base portion
of the cap for attaching the cap to a collapsible tube. This
threaded cap is constructed of a single material. However,
this closure membrane is not an integral part of the shoulder
of the container.
U.S~ Patent 2,937,795 discloses a domed shaped dispensing
closure for a collapsible tube. In this embodiment, the domed
shaped closure has a crossed slit membrane and is attached
directl~ onto the top of the collapsible container. This
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closure membrane and upper container shoulder portion are not
one integral part.
U.S. patent 3,669,323 discloses a one~way valve insert
for collapsible dispensing containers. This is an insert that
fits below the slot opening of the closure. This embodiment,
like the embodiments of the other patents, is a multi-piece
unit which requires assembly.
The present self-closing dispensing membrane closure is
an improvement over the various prior art closures. In the
present closure, the closure membrane is an integral part of
the shoulder of the container. The closure membrane and
shoulder are molded as one piece. This obviates the need for
assembly and removes the potential for leakage. This results
in a savings in time and money.
BRIEF DESCRIPTION OF THE INVENTION
This invention is directed to a tubular container which
has a membrane closure wherein the shoulder of the tubular
container and the membrane closure are an integrally molded
piece. The tu~ular container can be a collapsible container
or a non-collapsible container. It can also be a tubular
container in which the force on the contained product is
supplied by a piston. The membrane closure provides for a
positive dispensing of the contained product. Product is
dispensed by applying a force onto the product. This can be a
squeezing force when it is being dispensed from a tubular
container and a force applied by a piston for a pump
container. When the force pushing the product ~rom the
container is released, the membrane closure closes and cuts
off the flow of product. This also protects the product near
the opening from drying or becoming encrusted during storage.
BRIEF DESCRIPTION OF THE DRAWINGS
Fiyure 1 is a perspective view of a collapsible container
having an integral dispensing closure.
Figure 2 is a side view of the shoulder and dispensing
closure.
Figure 3 is a side view of the tube portion of the
dispensing container.
Figure 4 is a top view of the dispensing closure showing
a single slit.
Figure 5 is a top view of the dispensing closure showing
two slits.
Figure 6 is a side view of a preferred embodiment of the
dispensing closure with the closure elevated above the
threads.
DETAILE~ DESCRIPTION OF THE INVENTION
In Figure 1, there is shown tubular container 10 having a
tube portion ll sealed at the bottom at 12. The upper portion
of the tubular container consists of shoulder 15 which has
shoulder wall 16 and exit nozzle 17. On the exterior of the
exit nozzle, there is shown threads 18 for attaching a
threaded cap. The top portion 19 will have one or more slit
openings.
In Figure 2 and Figure 3, there is shown the shoulder
section 15 and the tube section 11 respectively. The tubular
portion ll has an upper opening 13 defined by rim 1~. The
shoulder portion 15 has a vertical portion 21 which terminates
in rim 20. Rim 20 defines aperture 22. In assembling the
shoulder 15 onto the tube 11, the vertical portion 21 extends
downward into opening 13 of the tube portion 11. The two
portions are then heat sealed. It is also an embodiment where
the vertical portion 21 of the shoulder extends down over the
wall of tube 11 and is then heat sealed. This can be by any
convenient heat sealing technique, including RF sealing and
ultrasonic sealing.
Figure 4 and Figure 5 show configurations for the
openings in the membrane closures on the nozzle portion of the
shoulder. In Figure 4, there is shown to be one slit opening
23 while in Figure 5 there is shown to be two slit openings,
23 and 24, which slit openings intersect. These two slit
openings need not intersect, and further, there may be more
than two slit openings.
Figure 6 sets out an alternate embodiment for the
shoulder portion. In this embodiment, the slit region 19 is
elevated above threads 18 by sidewall 26. This is in the
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nature of a hat type of dispensing slit arrangement. As with
the prior embodiments in this embodiment, the shoulder is a
single molded piece.
The entire shoulder portion is molded as a single piece,
including the membrane 25 on the top portion. This can be
conveniently accomplished by compression molding. Since the
shoulder portion is constructed as one piece, there is removed
the likelihood of leakage at joints. The slits 23 and 24 are
cut into the membrane 25 at a convenient time. This can be
after the shoulder portion has been molded and prior to
bonding to the tubular container portion, after attachment to
the tubular container portion, or after the tube has been
filled with a paste-like product.
The tube portion and shoulder portion can be made out of
any single or multilayer compatible materials. These include
polyolefin, polyester polymers and copolymers, including
polyethylene, polypropylene, vinyl acetate, and ethylene-vinyl
acetate copolymers, polyethylene terephthalate polymers and
polyethylene terephthalate copolymers.
