US2805790A - Plastic containers and packaging thereof - Google Patents

Description

P 0, 1957 R. E. SMUCKER 2,805,790

PLASTIC CONTAINERS AND PACKAGING THEREOF Filed Aug. 24, 1954 2 Sheets-Sheet 1 22 A I I II I I l I I I 1 76 20 22 i A w K0527? ljmzzcier' Par/3??" & arzer .iiaarneys Sept. 10, 1957 R. E. SMUCKER PLASTIC CONTAINERS AND PACKAGING THEREOF Filed Aug. 24, 1954 2 Sheets-Sheet 2 United States Patent PLASTIC CONTAINERS AND PACKAGING THEREOF Robert E. Smucker, Fort Worth, Tex., assignor to Crown Machine and Tool Company, Fort Worth, Tex., a corporation of Texas Application August 24, 1054, Serial No. 451,801

2 Claims. (Cl. 220-97) This invention is in the field of receptacles or containers of the cup type, although it is not necessarily limited in this respect, and it is a new and improved type of cup container specifically constructed to withstand the rough handling normally expected during shipment and storage.

A primary object of my invention is a cup-like container or vessel, which, when shipped in a group, stack or collection, is designed to nest or telescopically interfit so that it can be shipped in large numbers but in small bulk.

Another object is a container of the above type which, when nested in a stack, is constructed to withstand the axial or longitudinal compressive forces applied to it so that the sides will not split due to the outward fiexure or expansion applied to the sides of each container in the stack.

Another object is a thin wall plastic molded cup or container of the above type which, when nested in a stack, will carry the compressive load through the small closed end or bottom by a special compressive load carrying structure and not through the sides of the container.

Another object is a stack of nested plastic containers of the above type which can easily withstand the compressive load placed upon it.

Another object of my invention is a molded thin wall plastic container of the above type which is constructed specifically for shipment and storage in large quantities.

Other objects will appear from time to time in the ensuing specification and drawings in which:

Figure 1 is a vertical sectional view of a stack of my containers;

' Figure 2 is a vertical sectional view, similar to Figure 1 but on a reduced scale, of a variant single container; Figure 3 is a top view, partly in section, of my containers stored in a suitable shipping box; and

Figure 4 is a sectional view taken along line 4-4 of Figure 3.

In Figure l I have shown a stack of nested containers or cups, each individual container being substantially identical with the others. One of the containers, designated generally at 10, is shown in Figure 2 and has a frusto-conical shaped side wall 12 open at its large end at 14 and closed at the small end by a wall portion 16. A supporting bead or rim 18 is provided on the outside of the bottom wall to support the cup when it is placed on a surface. It should be understood that this supporting head can have any suitable configuration, such as radially extending ledges, or a pattern configuration, or any suitable design.

The container is made generally of plastic and has a very thin wall; for example, in the neighborhood of .020 inch. The material is relatively clear and transparent. The sides of the container diverge slightly at approximately a angle and therefore containers of this type can be nested or stacked one inside the other as shown in Figure 1 so that they will occupy a minimum amount ICC the nature of a reinforced or thickened section in the wall of the cup. The shoulder is disposed to face away from the closed bottom toward the open end or towards the top of the container and is positioned relatively close to the bottom.

Thus when containers of this type are nested or stacked one inside the other the shoulder 20 on each container will engage the bottom of the cup that is placed inside of it as shown in Figure l. The outside diameter of the bottom of each container lies generally between the inside and outside diameters of the shoulder so that one container will slide fully inside of the other. The shoulder of one cup will engage the outer peripheral edge 22 of the cup stacked inside of it.

It is also desirable that the supporting head 18 on the bottom be disposed within the confines of the shoulder so that it does not touch the shoulder and prevent the containers from fully seating.

For shipment or storage, the containers may be stacked and disposed in a suitable shipping carton. For example in Figures 3 and 4, I have shown the containers in stacks 24 of twenty-five each with twenty-five stacks to a carton. The carton, designated generally at 26, can be a suitable cardboard or wooden box of any conventional type. I have found that with previous types of plastic cups I could only pack twenty-five rows of 10 cup stacks which is a total of 250 plastic containers per shipping carton. With my new type of cup I can increase each stack, which means that I can ship 925 containers in a single carton without any breakage.

It will be realized that whereas I have described and illustrated a practical and operative device; nevertheless, many changes may be made in the size, shape, number and disposition of parts without departing from the spirit of my invention. I, therefore, wish my description and drawings to be taken as in a broad sense illustrative or diagrammatic, rather than as limiting me to my precise showing. For example, in Figure 2 a lip is provided around the rim of the container to prevent splitting by strengthening the edge.

' The use, operation, and function of my invention are as follows:

I provide a specific design or construction of cup having a very thin wall which at the same time is very durable and strong, and is made out of a transparent or clear plastic. Although it is not limited to this respect to a particular plastic, a plastic is best for my purposes. During shipment the cups are nested or stacked one inside the other and the outwardly facing abutment or shoulder near the bottom of each cup engages the bottom of the next adjacent cup so that in efiect the cups as stacked rest entirely upon these shoulders. Thus, any compression loads on a stack of containers will be transmitted through the shoulders and not through the sides of the cup. Thus, although the sides slightly engage each other, nevertheless they will not be flexed outwardly or expanded. I have found that if the cups are stacked so that the load is carried by the sides, 10% to 15% breakage due to splitting of the sides of the cups will occur when they are shipped in large quantities. It is important that the bottom of each cup engage the shoulder in the next cup so that the compressive force will be carried through the shoulders and not through the sides of the cup. For this reason, the outside diameter of the bottom of each cup should lie between the inside and outside diameters of the shoulder. If the outside diameter were larger, .the bottom of one cup would not, engage the shoulder of the next. If the inside diameter were smaller, the bottom of one cup would slide inside the shoulder of :theuother, and the sides of. each Icup would be flexed outwardly and would probably split.

-I ,.have. stated that the .cups are made of plastic and course this material is in general use at the present time. have found that I can use a plastic tomaterially reduce the thickness :of the walls of the .cup and at thesame time the 'weight will be substantially reduced; But. plastic has'a certain, progressive splitting or tearing characteristic such that when it has started splitting, it will be greatly accelerated by any compressive forces. The same is true of, an expand ng force. By theprovision of the annular shoulder in the bottom of each cup near the bottom, the compressive force will be transmitted actuallyfrorn one shoulder to another and the sides will not be flexed outwardly. Only'the topmost cup .in a stack will have a compressive force applied through .its walls, and breakage will be materially reduced if not completely eliminated. Thus, this shoulder in effect protects the thin walls of each cup. Atthe same time, the shoulder does. not in crease the spacing of the cups as it is so positioned near the bottom that the shoulder of one .cup .contacts the bottom of the next just before the telescoping walls of the two containers engage each other, firmly. I have found that the shoulder in each cup should be high enough so that a slight clearance exists between thewalls of the cups. If the walls engage each other, the cups will be difficult to separate because a slight closed vacuum will be present in the bottom of each cup. It should be understood that cups of this type are intended to be used with automatic filling equipment. Therefore, it is very desirable, if not absolutely necessary, that thecups be easily separated so that stacks of cups can be handled by automatic filling equipment. If a slight vacuum exists between the cups, they can not .be used with automatic filling equipment lest it should hinder the operation of such equipment.

I have shown a lip 28 in Figure 2 and it .should be understood that this can be used in the cups in Figure 1.

The provision of the lip around the top of the cup, as in Figure 2, in addition to strengthening the rim also enables a polyethylene 'cap to be used on the cupafter it is filled.

The shoulder in the bottom of eachcup has three functions: first, it prevents the formation of a vacuum; second, it prevents splitting of the sides of the cups; third, it strengthens the bottom of the'cup.

While I have shown and described a preferred form .of my invention, it should be understood that vmany changes, alterations and substitutions can be made. For example, the shoulder need not necessarily be con- :tinuous, and in the claims it should be understood that .the

term ?shoulder or abutment doesnot necessarily mean a continuous rim although I have found that a continuous 4 rim is the easiest to manufacture. I therefore wish that my invention be unrestricted except as by the appended claims.

I claim:

1. A cuplike, thin walled, completely integral, frusto conical container formed of a molded plastic material, and having a frusto conical thin side wall surface open at its large end and closed at its small end by an integral lateral bottom wall, the side wall terminating at the point of junction with the bottom wall, and a continuous integral thickened portion extending inwardly from the side wall adjacent and integral with the bottom wall at the point of junction between the side and bottomwallsand extending in a radial direction from one surface of the side wall, the outer surface of the side wallbeing uninterrupted and smooth opposite the thickened portion, the thickened portion having a longitudinal inner surface which is substantially cylindrical and concentric with the-:axis of the container, the upper surface of the thickened portion facing outwardly and lying in a lateral plane generally perpendicular :to the axis oflthe container and constituting a continuous annular, shoulder. adapted to engage an annular marginal portionof the bottom wall-of a nested container of like size and shape, the axial dimension .of the integral thickened portion from the inner surface of the bottom wall to the edge of the continuous annular shoulder being limited, -such that the side Walls of such containers, when nested, will be slightly separated due to engagement between the thickened portions to prevent the formation of .a vacuum, the diameter of the outer surface of the bottom wall being less than the outside diameter of the continuous annular shoulder, measured at its. point-of junction with .the inner surface of the side wall, but greater than the diameter of the longitudinal inner surface of the thickened portion, the thickenedportion being integral with the side wall throughout. the thickened portions entire axial and circumferential extent, the integral thickened portions of a nested stack of such containers constituting, as a group, a substantially vertical supporting column constructed to pass axial loads directly from one thickened portion to another through the engaged annular marginal portion of each bottom wall.

2. The .structure of claim 1. further characterized in that the thickness of theside wall of the frusto conical container is on the order of.020".

ReferencesiCitedin the file of this patent UNITED STATES PATENTS 703,711 Seaman July 1, 19.02 1,198,596 Strange. Sept. :19, 1916 2,088,181 Swift July 27, .1937 2,239,093 Giller, .Apr. 22, 1941 2,328,543 Bauman ...Sept. 7, 1943 2,492,152 vHollowell Dec. 27, 1949 2,530,124 Kieckhefer Nov. 14', 1950

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