Dispensing – Collapsible wall-type container – Plural container and/or compartment
Reexamination Certificate
2000-02-07
2001-05-01
Shaver, Kevin (Department: 3754)
Dispensing
Collapsible wall-type container
Plural container and/or compartment
Reexamination Certificate
active
06223943
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method and apparatus for molding squeeze tube containers for storing and dispensing flowable products and particularly to a technique for molding a multichamber squeeze tube in which mating mold surfaces form an opening through a transverse end wall between tubes on the dispensing container, and to the squeeze tube container formed thereby.
2. Background Information
Containers formed of pliable resin which can be squeezed to dispense a flowable product are well known. Some of these containers have two or more chambers containing separate components which are mixed as they are dispensed. The known multichamber squeeze containers have a separate end piece which is preformed and then fixed to the separately formed tube sections or, in some cases, is molded to preformed tubular sections. In the latter case, the preformed tubes are supported in a mold which is then filled with flowable resin, or are sealed with a laminate. The resin hardens to form the end piece in which the ends of the tubes are imbedded. In some cases, the end piece is complex and can have multiple pieces which require assembly. The multiple chambers are filled with the different flowable products from the opposite ends of the tubes which are then closed, usually by flattening and sealing. The end piece has dispensing openings for each of the chambers, typically sized to effect a desired mix of the flowable products which are dispensed by squeezing the tubes. The squeezing force applied to the outer tube is transmitted to the inner tube or tubes through the intervening flowable product or products.
These known multichamber squeeze tubes require separate steps to form the tubes, load them into a mold and then mold the dispensing end piece to engage the preformed tubes. In other cases, the tubes and end pieces are separately formed and then joined. In both cases, several steps are required to form a multichamber squeeze tube which adds to the cost and production time.
It is also known to mold multichamber squeeze tube containers as a single unit as is disclosed in U.S. patent application Ser. No. 09/164,143, filed Sep. 1, 1998, and having common ownership with one of the inventors of the subject invention.
There is a need for an improved method and apparatus for molding a multichamber squeeze tube that can be made quickly and inexpensively.
More specifically, there is a need for such an improved multichamber squeeze tube that uses a simple mold.
SUMMARY OF THE INVENTION
These needs and other are satisfied by the invention which is directed to a method and apparatus for molding a multichamber squeeze tube having at least two tubes with a first tube nested inside a second tube. The first chamber is formed inside the first tube and a second chamber is formed between the first and second tubes. A transverse wall extends across first ends of the first and second tubes to close off the first and second chambers and cylindrical neck portions preferably extend upwardly from the transverse wall. The tubes, the transverse wall and neck portions are integrally molded as a single piece. The transverse wall is formed with at least one dispensing opening extending therethrough and aligned with the first chamber and at least one second dispensing opening extending therethrough and communicating with the second chamber. After the first chamber is filled with a first flowable fluid and the second chamber is filled with a second flowable fluid through the second ends, the second ends of the tubes are closed off, preferably by flattening and sealing.
The transverse wall of the container has an annular stepped wall portion in it between the first and second tubes and the dispensing openings for the second tube are through that stepped wall portion. The stepped wall portion of the transverse wall is generally cylindrical and parallel with the walls of the tubes and has generally planar annular wall portions on both sides of the stepped wall portion.
In the method and apparatus of this invention, the stepped wall portion and openings through it are formed by the outer core and an insert cavity member in the mold for forming the squeeze tube container. The outer core has a first annular rim on its end surface and the insert cavity member has a second annular rim on its end surface which is smaller than the annular rim on the outer core so the rims are radially spaced apart when the mold is closed. At least one of the rims has at least an arcuate rib on a side surface facing the other rim. The arcuate rib has a parting line contact surface with the other rim so as to form an opening through the stepped wall portion. The arcuate rib(s) are preferably located on the annular rib on the insert cavity member.
The invention embraces a method and apparatus for molding a multichamber squeeze tube, a squeeze tube so molded, and a combination of the squeeze tube with a cap which engages the neck such as by complementary threads on the inner surface of a peripheral skirt of the cap and the outer surface of the cylindrical neck of the squeeze tube.
REFERENCES:
patent: 1535529 (1925-04-01), Hopkins
patent: 3227319 (1966-01-01), Rosier
patent: 3747804 (1973-07-01), Raaf et al.
patent: 4211341 (1980-07-01), Weyn
patent: 4461403 (1984-07-01), Prahs
patent: 5076470 (1991-12-01), Hatakeyama et al.
patent: 5388727 (1995-02-01), Jouillat
Richmond Thomas Michael
Wiegner Thomas F.
Bristol-Meyers Squibb Company
Buechner Patrick
Eckert Seamans Cherin & Mellott , LLC
Shaver Kevin
Westerhoff Richard V.
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