US3471055A

US3471055A - Nestable container with bottom stacking

Info

Publication number: US3471055A
Application number: US778511A
Authority: US
Inventors: Bryant Edwards
Original assignee: Illinois Tool Works Inc
Current assignee: Dart Container Corp
Priority date: 1967-02-08
Filing date: 1968-11-25
Publication date: 1969-10-07
Anticipated expiration: 1986-10-07

Description

Oct. 7, 1969 a. EDWARDS 3,471,055

NESTABLE CONTAINER WITH BOTTOM STACKING Original Filed Feb. 8, 1967 Brno/7f m,-

His Af f'ys v United States Patent 3,471,055 NESTABLE CONTAINER WITH BOTTOM STACKING Bryant Edwards, Clarendon Hills, Ill., assignor to Illinois Tool Works Inc., Chicago, Ill., a corporation of Delaware Original application Feb. 8, 1967, Ser. No. 614,650. Divided and this application Nov. 25, 1968, Ser. No. 778,511

Int. Cl. 365d 21/02 US. Cl. 220-97 7 Claims ABSTRACT OF THE DISCLOSURE A nestable container of thin-Wall plastic construction having a stacking protuberance in the bottom wall thereof to limit the extent of telescopic association of a plurality of stacked containers, the axis of the stacking protuberance being tilted with respect to the axis of the container to provide overlap between adjacent protuberances of adjacent containers for stacking purposes.

This is a division of Ser. No. 614,650, filed Feb. 8, 1967.

BACKGROUND OF THE INVENTION Field of the invention This invention relates to the field of nestable thin-wall plastic containers of the disposable variety incorporating stacking means in the bottom wall thereof having a configuration which prevents jamming between adjacent telescopically arranged containers.

It is well known that such thin-walled nestable or open mouth plastic containers will jam or stick together when stacked in nested relationship and subject to normal handling functions, thereby preventing their ultimate use. It is possible to incorporate a stacking facility in the side wall of such containers as shown in my Patent 3,139,213, and this technique overcomes the jamming problem noted, and thus has been widely employed throughout the plastic container industry in the United States and other countries of the world.

In some instances, it is desirable to incorporate a stacking facility at a place other than the container side wall to provide more area for printing of the container, and to maintain a smooth side wall shape for aesthetic purposes. Where this is desired, resort must be had to rim stacking or stacking means incorporated in the bottom wall of a container. Rim stacking may be successfully employed with certain types of containers, usually those which do not have a substantial volume or capacity due to the limitations placed on the axial height of the rim area. In the final analysis, rim stacking cannot be successfully employed over the wide range of container sizes which have been distributed in the market place, and thus bottom sta king techniques are the most likely alternative to the side wall stacking techniques of my aforesaid patent.

Description of the prior art Several types of bottom stacking have been proposed for seamless thermoplastic containers such as, for example, those techniques which have been disclosed in US. Patent Nos. 2,988,258 and 3,027,596. These patents disclose representative forms of bottom stacking means in seamless thermoplastic containers which are typical of the two basic forms from which subsequent developments have been made. In some cases, the bottom stacking constructions of the prior art have not always met industry desires of an easily formed, consistently functioning stacking device which does not interfere, to any great extent, with the volume or capacity of the container. Even in 3,471,055 Patented Oct. 7, 1969 "ice those cases where the bottom stacking device may not be such that it conserves the volume or capacity of the container, the prior art bottom stacking techniques have either been too difficult to remove from mold parts or have been easy to remove from the mold parts and yet have not functioned as stacking devices in a consistent manner required by industry standards.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved stacking device in the bottom wall of a thinwall thermoplastic nestable container.

Another object is to provide a thin-wall plastic container having a bottom stacking device which is not difficult to form, consistently functions as a stacking device and yet does not interfere, to any great extent, with the volume or capacity of the container.

A further object of the present invention is to provide a bottom stacking means in a thin-walled seamless thermoplastic container which, in certain forms of the present invention, is easy to remove from molding machinery and yet provides a stacking function consistent with industry standards.

These and other objects and advantages of the present invention are attained by the provision of a stacking protuberance formed in the bottom wall of a seamless, nestable container of thermoplastic material, the stacking protuberance including an upper stacking shoulder and a lower stacking shoulder which are connected by an intermediate wall section, the axis of the stacking protuberance being tilted with respect to the axis of the container to provide overlapping between the upper and lower stacking shoulders of telescopically arranged containers for stacking purposes.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary perspective view, partially in section, illustrating a seamless thin-wall plastic container having a bottom stacking device coming within the scope of the present invention;

FIG. 2 is an enlarged fragmentary sectional view showing stacking of a pair of adjacent containers, each of the containers utilizing the stacking means shown in FIG. 1 of the drawing;

FIG. 3 is a fragmentary perspective view, partially in section, after the fashion of FIG. 1, and depicting another stacking embodiment of the present invention;

FIG. 4 is an enlarged fragmentary sectional view also similar to FIG. 2 of the drawings which utilizes the stacking means illustrated in FIG. 3;

. FIG. 5 is a fragmentary perspective view, partially in section, similar to FIG. 1 showing the last illustrated form of stacking device constructed in accordance with the present invention; and

FIG. 6 is an enlarged fragmentary sectional view similar to FIG. 2 of the drawings, and showing stacking of a pair of nested containers utilizing the stacking means illustrated in FIG. 5 of the drawing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The general form of cup or container 10a which incorporates the stacking facility of the present invention is illustrated in FIG. 1 of the drawings. The cup or container 10a is preferably made into a seamless, thin-wall construction from a thermoplastic material such as polystyrene, and is formed into a frustoconical shape including a bottom wall 12a, and a peripherally continuous side wall 14a which diverges upwardly and outwardly therefrom and which terminates in a rim portion 16a in the vicinity of the open mouth or open upper end of the container 10a. While the side wall 14a may incorporate various types of finger gripping rings or protuberances to facilitate grasping as well as thermally insulate the hand of the user, there may be a desire to retain the smooth side walls shape as illustrated in the drawing when using the stacking facility of the present invention.

In accordance with the present invention, the stacking means or facility 18a is formed integrally with the bottom wall 12a of the container by conventional thermoforming techniques. As depicted in the form of the in- Vention shown in FIGS. 1-2, the stacking facility or means comprises a protuberance formed in the bottom wall 12a of the container which includes a lower external stacking shoulder 20a, an upper internal stacking shoulder 24a axially upwardly spaced from the lower external stacking shoulder 20a, and an intermediate connecting wall section 26a which is tilted or inclined with respect to the axis of the container to provide overlapping for stacking purposes.

In the FIGS. 1-2 embodiment, the stacking protuberance 18a of each container a is radially inwardly directed whereas in the FIGS. 3-4 embodiment, the stacking means or protuberance 18b is radially outwardly directed. Thus, a lower stacking shoulder a in the FIGS. 1-2 embodiment will be generally aligned or coplanar with the bottom wall 12a of the container since the stacking protuberance 18a is radially inwardly directed relative to the bottom wall 12a and is connected to the bottom wall 12a as illustrated. FIGS. 3-4 on the other hand show the stacking protuberance 18b with the upper stacking shoulder 24b generally aligned with the bottom wall 12b in view of the general outward disposition of the stacking protuberance 18b relative to the bottom wall 12b and the connection of the stacking protuberance 18b thereto. In either case, the tilting or inclination of the stacking protuberance will provide an overlapping between at least portions of the upper and lower stacking shoulders 20a, 24a or 20b, 24b associated with adjacent containers to provide stacking interference which is greater than the material thickness of the container at the point of overlap or contact. Thus, although there are portions of cooperating stacking shoulders which do not come into engagement with each other, it makes no difference in what position the containers are oriented relative to one another since in any case the stacking interference or overlapping of the type mentioned will be provided.

While the FIGS. 3-4 embodiment will conserve the volume or capacity of the container, the same will not be true of the FIGS. 1-2 embodiment. However, in both of the embodiments, the

stacking protuberances

18a and 18b can be easily removed from the molding apparatus since there is no annular or peripheral undercut involved from the standpoint of stripping containers having such protuberances from their mold parts.

The last described embodiment illustrated in the drawings is shown in FIGS. 5-6. In this particular instance, there are a plurality of stacking protuberances 180 for each container 100, each stacking protuberance 18c having the lower stacking shoulder 20c, the upper stacking shoulder 24c, and the intermediate wall section 26c. It will be noted that the lower stacking shoulder 20c and the upper stacking shoulder 240 of adjacent stacking protuberances 18c are joined to each other by way of a second intermediate wall section 32 which finds no counterpart in previously discussed embodiments. However, in this form of the invention, there is no connecting wall portion between the upper stacking shoulder of any stacking protuberance and the bottom wall of the container except for the stacking protuberance at the far left in FIG. 16 of the drawings. The stacking protuberance 18c at the far right in FIG. 16 of the drawings is joined to the bottom wall 12c through the intermediate wall section 260.

The least optimum stacking position is shown for a pair of nested containers in FIG. 6 of the drawings, and it should be recognized that when this occurs, the bottom wall to the far right as viewed in FIG. 6 will cooperate with the upper stacking shoulder 240 of a lower-most container in limiting the extent of telescopic association of adjacent containers. At any other position, the stacking protuberances 18c are designed on adjacent containers to effectively limit jamming or sticking of the containers in the same manner as described in the previous embodiments.

The thin-wall character of the material which is on the order of .01 in thickness and is inherent flexibility which is derived from the thermoplastic material will provide a certain amount of resiliency in various forms of the invention where the structure of the stacking protuberance will work with and not against this desired result. It is conceivable that there could be various stacking configurations which, although constructed in accordance with the present invention, will not take advantage of the resiliency of the material to provide a shock absorbing technique for the containers when subjected to the normal handling functions. This is, however, a very desirable result, and should be utilized in all instances where possible.

I claim:

1. A seamless container of thermoplastic material having a bottom wall and a side wall which diverges upwardly and outwardly therefrom to an open upper end, and a hollow stacking protuberance formed in the bottom wall of said container including an upper stacking shoulder and a lower stacking shoulder connected by an intermediate wall section, the axis of said stacking protuberance being tilted with respect to the axis of said container to provide overlapping between the upper and lower stacking shoulders of telescopically arranged containers for stacking purposes.

2. The container as defined in claim 1 wherein the protuberance is axially, inwardly directed from the juncture of the bottom and side wall of the container.

3. The container as defined in claim 1 wherein the protuberance is radially, outwardly directed from the juncture of the bottom and side wall of the container.

4. The container as defined in claim 2 wherein the lower'stacking shoulder of the protuberance is transversely aligned with the bottom wall of the container.

5. The container as defined in claim 3 wherein the upper stacking shoulder is transversely aligned with the bottom wall of the container.

"6. The container as defined in claim 1 including a plurality of stacking protuberances provided in the bottom wall of the container and aligned in the same direction relative to one another, each said protuberance being tilted with respect to the axis of the container.

7. The container as defined in claim 6 wherein the upper stacking shoulder, the lower stacking shoulder and the intermediate wall section of each stacking protuberance are configured in the shape of a sawtooth construction.

References Cited UNITED STATES PATENTS 3,131,845 5/1964 Sherlock et al. 2291.5 3,203,611 8/1965 Anderson et al. 220-97 X 3,393,826 7/1968 Brown 220-97 GEORGE E. LOWRANCE, Primary Examiner