Plastic and nonmetallic article shaping or treating: processes – Mechanical shaping or molding to form or reform shaped article – To produce composite – plural part or multilayered article
Reexamination Certificate
1998-12-04
2001-04-03
Ortiz, Angela (Department: 1732)
Plastic and nonmetallic article shaping or treating: processes
Mechanical shaping or molding to form or reform shaped article
To produce composite, plural part or multilayered article
C264S266000, C264S318000, C264S319000
Reexamination Certificate
active
06210621
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a plural chambered dispensing tube composed of a tube head, a tube body and a partition which divides the tube into separate and discrete compartments. More particularly, this invention relates to an improved method of making the aforementioned tube.
Many products on the market today, e.g., peroxide toothpastes, hair coloring, epoxy adhesives, and the like, require that the components therein be kept separate during storage (due, for example, to instability of the components) but dispensed simultaneously for use. Many of these products require costly dispensers and fabricating and packaging equipment to produce dispensing means which deliver the separate components simultaneously.
Products consisting of two flowable components such as pastes, gels, or liquids which must be stored separately are desirably packaged in containers having two compartments. Tubular bodies having chordal partitions are useful in providing two-compartment containers for two-component products which must have predetermined proportions of their components mixed at the time or point of use.
A number of longitudinally partitioned tubular bodies and dispensing containers having chordal partitions have been disclosed in the art. Reference is made, for example, to U.S. Pat. Nos. 3,290,422; 3,506,157; 3,307,738; 5,076,464; 5,244,120; and 5,269,411. However, none of the aforementioned patents has solved all the problems associated with providing longitudinally partitioned tubular bodies such as, for example, simplicity of manufacture, at a low cost and without changing consumers' habits.
There are many cleaning, drug and personal products which are marketed today in single dispensing packages which could be dramatically improved if an inexpensive dual dispensing device were available. Many of the dually dispensed products which are currently on the market and those which are not yet on the market can be dispensed from a tube rather than more costly dispensing means. A tube is a dispensing device that is readily available, familiar to most consumers, is comparatively less expensive and does not require elaborate filling equipment. If commercially available tubes can be easily and cheaply converted into dual-dispensing devices, it would be a great advantage to those either currently marketing or planning to market dually-dispensed products.
One method for making a multi-chambered dispensing device involves connecting a pre-finished tube body with a pre-finished tube head and then pushing a partition, which is structured in folded form and resilient in its lengthwise and crosswise directions, into the tube body. One of the crosswise sides of the partition may be connected (e.g., by gluing, heat sealing, etc.) to the tube head while the other crosswise side of the partition may be connected to the opposite side of the tube body. The inherent spring forces of the partition, which act in the lengthwise and crosswise directions, cause the lengthwise sides of the partition to press against the inside of the tube body and the crosswise sides of the partition to press against the tube body and the tube head (unless gluing on the inside of the tube head is provided).
A drawback to the method described above is that the step of installing a partition into the interior of a pre-finished tube body requires manufacturing subassembly steps.
Another method for making a multi-chambered dispensing device involves providing a pre-finished tube head connected to a partition by mechanical means and introducing the partition with the tube head attached thereto into a tube body to such an extent that the tube head can be connected to the tube body in a known manner, e.g., bonding the tube head and the tube body along the external circumference of the tube head. Although the introduction of the partition into a tube is simpler in this method than in the prior art method described above, this method, unlike the method described above, requires the additional step of connecting the tube head and the partition together prior to introduction of the partition into the tube body.
One problem which has been encountered with some plural-chambered dispensing tubes is that the partition dividing the tube into plural chambers tends to moves about, thereby adversely affecting dispensing ratios. Leakage between the chambers as a result of relatively weak bonds between the partition and the rest of the tube has also been a problem. Thus, in plural-chambered dispensing tubes, it is desirable that the means for dividing the tube into two or more chambers will provide uniform dispensing ratios of the components stored therein and prevent substantial leakage of the separated components.
Therefore, a primary object of this invention is to provide a method of making a plural-chambered dispensing tube which securely bonds the partition therein to the tube head and the tube body so as to allow uniform dispensing ratios and prevent substantial leakage between chambers.
Another object of this invention to provide a simpler and more economical method for making a plural-chambered dispensing tube having the characteristic set forth in the aforementioned object.
These and other objects which are achieved according to the present invention can be discerned from the following description.
SUMMARY OF THE INVENTION
The present invention provides a method for forming a plural-chambered dispensing tube composed of a tube head, a tube body and a partition disposed in the tube body and the tube head so as to divide the tube into two discrete chambers. In the method of this invention, a molten resin material is molded into a tube head while a pre-finished tube body having a partition housed therein is disposed within the molten resin material. In other words, the pre-finished tube body and partition become connected to the tube head as the latter is being molded.
More specifically, the method of this invention broadly involves the steps of:
(1) providing a partition-tube body assembly comprising a hollow tube body and a partition disposed in the tube body so as to divide the tube body into two discrete chambers, the assembly having a front end composed of a front circumferential end of the tube body and a head of the partition,
(2) providing a liquid resin material to be molded into a tube head and inserting the front end of the assembly into the molten resin material; and
(3) molding the tube head from the resin material while the front end of the assembly is disposed within the molten resin material so as to mold the tube head onto the front end of the assembly such that (i) edges of the partition head are bonded to an interior surface of the tube head to divide the tube head into two discrete chambers and (ii) the tube head is bonded to the front circumferential end of the tube body, thereby forming the plural-chambered dispensing tube.
A major advantage of the method of this invention is that it forms a uniform seal between the partition and the tube head, thus allowing uniform dispensing ratios and effective separation of the stored components.
Another advantage of the method of this invention is that it forms plural-chambered dispensing tubes with high efficiency.
A further important advantage provided by the method of this invention is that the end of the partition which runs into the tube head connects with the tube head as the latter is being formed. This itself represents a significant simplification of the production of a plural-chambered dispensing tube.
REFERENCES:
patent: 2713369 (1955-07-01), Strahm
patent: 3286010 (1966-11-01), Groningen
patent: 4021524 (1977-05-01), Grimsley
patent: 4065536 (1977-12-01), Lucas
patent: 4518554 (1985-05-01), Hatekeyama et al.
patent: 5219373 (1993-06-01), Hatekayama et al.
patent: 5292034 (1994-03-01), Keller
patent: 5705112 (1998-01-01), Gram
patent: 197 12 736 C1 (1997-03-01), None
Duncan Thomas J.
Usen Norman
Enamelon Inc.
Frenkel Stuart D.
Ortiz Angela
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