US3171458A - Plastic container - Google Patents

Description

March 2, 1965 B. STRONG 3,171,458

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INVENTOR- United States Patent 3,171,458 PLASTIC CONTAINER Bernard Strong, Beverly Hills, Calif., assignor to Strong Plastics lnc., Los Angeles, Calif., a corporation of California. v

Y iled Aug. 6', 1963, Ser.'No. 300,263 3 Claims. (Cl. 150-.5)

This invention relates in general to containers with closures and relates more specifically to an interlocking cap and container structure, and to the process for installing a cap upon a container.

Interfitted container closures are at least as old as the glass milk container and probably much older. Such a cap is simply rammed home into-a bottle mouth configuration and caused to hold by interfitting action.

Since the first development of such interference holding devices, there have been a great number of physical configurations and schemes for, attaching such caps. Some such schemes are very successful but have too great a cost. Others are less costly and have indifferent success.

It is an object of this invention to provide 'a container having an entrance opening which acts upon the cap for locking purposes, in contradistinction to prior methods having the cap lock onto the container.

It is a further object of this invention to employ dilatory material for the construction of an entrance opening into a container and causing the entrance opening to first expand and then contract after a closure device has been inserted into the expanded opening.

It is still another object of this invention to provide an entrance opening of a combination of physical and chemicalcharacteristics enabling the entrance opening to be dilated along a path which causes a return by elastic memory in such a manner that the return causes an initial lock upon a closure device within the closure, followed by a continuing enhancement of the interlock to a theoretical maximum attained with the passage of time.

It is still a further object of this invention to provide a container having a combination of chemical properties and physical form providing improved pour characteristics.

In accordance with these and other objects which will become apparent hereinafter, a preferred form of the present invention is disclosed in the accompanying drawings wherein:

FIGURE 1 is a fragmentary elevational view of the top portion of a container, with parts broken away in section, together with a closure cap in elevation, also with parts broken away in section, the container and cap positioned in exploded view relationship;

FIGURE 2 is a top view taken substantially along the direction of the line 22 in FIGURE 1;

FIGURE 3 is an enlarged fragmentary section of the lip of the bottle and the channel of the cap, in the condition obtained as the cap is installed initially upon the container;

FIGURE 4 is the same section as FIGURE 3 with the installing device removed to release the dilating force from the container, and the structure returned toward its original condition; and

FIGURE 5 is a section taken along 5-5 of FIGURE 1.

To illustrate the invention, a classic bottle of narrow neck construction is employed.

The entrance opening into the bottle 10 is defined by a wall structure having a cross section configuration which is shaped like a question mark in form. This form as shown in the section portion of FIGURE 1, is provided in the manner of an expansion joint employed in large pipe line construction. That is, a rounded portion 12 interconnects between a flat top wall 14 and a vertical leg section l6.

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The material from which the bottle 10 is formed is capable of being molded into a given form, and thereafter being forced out of that natural form, but so long as the material is not forced beyond its elastic limit, it will return by elastic memory substantially to its original condition. Y The preferred material for this'invention is a linear polyethylene, a thermoplastic synthetic resin.

Returning then to the physical form of the invention, an entrance opening 17 is defined by an edge Wall 18, which wall is chamfered to an acute angular edge 20 lying to the side of the wall 14 interiorly-of the container, and this sloping edge wall 18 extends outwardly to a greater sectional dimension than the opening at the acute angle knife-edge 20.

Thus, because of the physical and chemical combination, the bottle 10 is provided with an entrance opening defined by a dilatant annular edge wall having the characteristic of returning to substantially its original size and position after removal of dilating influences.

Therefore, a closure cap 22 may be installed upon this bottle 10 in a new and novel manner and gripped more strongly as time passes after installation. This novel result is obtained by providing a cap 22 with a cup portion- 24 formed slightly larger on the external cap surfaces than the natural diameter of the entrance opening 17, and then placing a plunger 26, as shown in FIGURE 3, into the cup 24 and forcing the cap through the entrance opening 17. Such force will cause the entrance opening to dilate and to roll inwardly of the container as shown by the full lines of the section in FIGURE 3. Note by comparison, the original position of theedge 20 shown in dotted outline. By so forcing the cap, the opening is both dilated and rolled upon itself somewhat, and thus is provided with internal stresses which will tend to relieve. themselves by causing the material to return to its original condition by elastic memory.

Accordingly, after the plunger 26 is removed, the edge 20 immediately returns toward its original condition as shown in FIGURE 4. Note, however, that the immediate return is not fully to the pre-dilation condition shown in the dotted outline form in FIGURE. 3. Nevertheless, the edge 20 is firmly imbedded into the material of the cap 22 and thus the cap can not be removed without first tearing or otherwise destroying the cap material. Furthermore, as time continues, the elastic memory will cause the edge wall 18 to return more nearly to its original condition, thus increasing the interlock of the bottle into the cap material and enhancing the locking action, in contradistinction to a general relaxing available in some instances with other devices.

Because the edge 20 is a smooth knife edge, it would be quite possible to rotate the cap around the central axis of the opening and in this manner possibly destroy the cap and the seal created. Therefore, the wall 18 is thickened at least at one place, as shown by the reference character 30 in FIGURE 1, and as seen in the sectional view of FIGURE 5. In this manner, the enlarged portion forms an interference fit which prevents rotational movement of the cap once installed.

The material which most perfectly suits the needs of this invention is polyethylene or othersemi-rigid plastic which has a memory. Some such plastic materials have an inherent characteristic which repels water and-water .based solutions or mixtures. Polyethylene is an'example. When such material is employed for the containerof this invention, pouring from the container is virtually drip proof. Liquid projects from the edge 20 with no tendency whatsoever to cling to the surface 18 and dribble. Therefore, the combination of this material together with the form of the container edge 'constitute'sanother new and unexpected result of this invention.

While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiments, it is. recognized that departures may be made therefrom within the scope of the invention which is therefore not to be limited to the de tails disclosed herein but is to be afiorded the full scope said edge wall being a frustrum of a cone sloping to an acute angular edge, said frustrum surface defining a cone projecting into the container and having an apex which is projectedfarther from the edge wall upon dilation of the edge wall; I

whereby, a-closure cap positioned closely within said opening when dilated will be gripped by the return thereof to its original condition.

2. A new and improved container closure, comprisingf a container having side walls defining an axis, a dilatant end wall having an entrance opening outlined by an edge wall encompassing said axis, said end wall extending substantially perpendicular to said axis out- Wardl'y from said edge wall, said' edge wall being chamfered to an acute angular edge, said edge wall being a frustrum of a cone, said frustrum defining a cone projecting into the container around said axis and having-an apex which is projected farther from the edge wall upon dilation of the edge wall;

said edge being to the side of said wall interiorly of said container and the edge wall sloping outwardly .to a greater sectional dimension than the opening at the said acute edge; I said dilatant end wall having an elastic memory causing the material to return substantially to its original condition after removal of dilating influences. 3. A new and improved container closure, comprising: a container having an entrance vopening defined by a wall structure having. a cross section configuration of .question mark form having a substantially-flat said opening encompassed by-an edge wall chamfered to an acute angular edge;

said flat top extending outwardly from said opening perpendicular to said vertical ,leg section;

said acute angular edge being tothe side of said edge wall interiorly of said container and the edge wall sloping outwardly to a greater sectional dimension than the opening at said acute edge;

said container wall structure being of dilatant material having an elastic memory.

References Cited by the Examiner UNITED STATES PATENTS,

2,099,055 11/37 Ferngren -.5 X 2,412,169 12/46 O'Neil 53-43 I FOREIGN PATENTS 830,737 3/ 60 -Great Britain.

FRANKLIN, T. GARRETT, Primary Examiner.

Claims (1)

1. A NEW AND IMPROVED CONTAINER CLOSURE, COMPRISING: A CONTAINER HAVING SIDE WALLS DEFINING AN AXIS, A DILATANT END WALL HAVING AN ENTRANCE OPENING OUTLINED BY AN EDGE WALL ENCOMPASSING SAID AXIS, SAID END WALL EXTENDING SUBSTANTIALLY PERPENDICULAR TO SAID AXIS OUTWARDLY FROM SAID EDGE WALL, SAID END WALL HAVING THE CHARACTERISTIC OF RETURNING TO SUBSTANTIALLY ITS ORIGINAL SIZE AND POSITION AFTER REMOVAL OF DILATING INFLUENCES; SAID EDGE WALL BEING A FRUSTRUM OF A CONE SLOPING TO AN ACUTE ANGULAR EDGE, SAID FRUSTRUM SURFACE DEFINING A CONE PROJECTING INTO THE CONTAINER AND HAVING AN APEX WHICH IS PROJECTED FARTHER FROM THE EDGE WALL UPON DILATION OF THE EDGE WALL; WHEREBY, A CLOSURE CAP POSITIONED CLOSELY WITHIN SAID OPENING WHEN DILATED WILL BE GRIPPED BY THE RETURN THEREOF TO ITS ORIGINAL CONDITION.

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