US2768667A - Container - Google Patents

Description

D. W. HILL CONTAINER Oct. 30, 1956 Filed Sept. 29, 1952 INVENTOR. Dona 1d (Hill BY W, X

United teme CONTAINER Donald W. Hill, Ladue, M0., assignor, by mesne assignments, to Crown Qork & Seal Company, ind, Balti more, Md, a corporation of New York Application September 2?, 1952, Serial No. 312,690

1 Claim. (Cl. 1519-59 This invention relates to containers for foods, medicines, chemicals and the like. It is particularly useful when these materials are stored in refrigerators or frozen food lockers.

Containers of this general class which have been utilized heretofore have been found faulty in that they lacked sufiicien-t ri idity and strength to Withstand stresses and strains imparted by pressure changes and other elements not directly related to the container itself and, in addition, they lacked means for preventing the escape and diffusion of gases and vapors from the container.

Further, the containers of this general class previously utilized lack characteristics imparting stacking facilities to aid in packing them for shipment.

The primary object of this invention is to provide a container which will have sufficient rigidity and strength that it will not become distorted by pressure changes due to condensation of gases Within the container or by reason of the weight and character of the contents.

A further object of the invention is to provide a container of suficient strength and rigidity to withstand destructive forces imparted by other bodies coming in contact with the outside surface of the same.

Another and more specific object of this invention is to provide a container so constructed that the thickness of its side walls is varied to provide an inwardly directed peripheral shoulder at the lower inside surface of the box thus insuring greater strength.

An additional object of this invention is to provide a container having a shoulder peripherally imposed on its lower inside side walls so as to provide for greater facility in stacking the same.

Another object of this invention is to provide a receptacle which may be tightly sealed at all times so as to preserve the contents of the same as well as to prevent the escape and diffusion of gases and vapors from the contents into the atmosphere. I

A further object of this invention is to provide a container which will maintain a tight seal at all times regardless of temperature conditions such as may contribute to differences in expansion and contraction of the materials of which the container and its closure are made.

Still further objects and the entire scope of applicability of the present invention will become apparent from the detailed disclosure given hereinafter. It should be understood, however, that the detailed description and specific illustrations, while indicating preferred embodiments of the invention, are given only by way of illustration, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

The body of this container is made preferably of a flexible, transparent, difiicultly distortable plastic material such as polystyrene. The closure of the container is made of an opaque, readily distortable, flexible material such as polyethylene. Notwithstanding that polyseal may be obtained as, for example; when products which initially give off a vapor are enclosed and the vapor is subsequently condensed under lowpressure.

Specifically, the airtight seal is realized by construct ing the closure of polyethylene or material of like characteristics and the container of polystyrene whereby at no time do the differences in coe'fiicient of expansion and contraction between the polystyrene body and the polyethylene cover strain the sealing relationship or break the seal. Polystyrene is subject to greater and more rapid expansion or contraction under temperature variations than polyethylene. These differences are compensated for by the closure structure and, in' addition-areindirectly utilized in the sealing operation of the con-' t ainer since the forces that are a direct result of said differences bear upon the closure structure and, in this" Way, tend to further effectuate the seal that is initially established by the cooperation of the body with the closure. Further, the tight, snug seal provided between the body and the closure is considerably enhanced by the adhesive aiiinity of the polyethylene for the polystyrene.

Specifically, the container body of the invention is adapted to cooperate with a closure structure of the general type described in considerable detail in the patent to Hill, No. 2,606,586, issued August 12, 1952, and comprising the cover it. The features of the closure structure disclosed therein are embodied in the present invention for substantially the same functions.

It should be noted that the molecular weight of the polystyrene employed may vary between 1,040 and 154,000, although the compounds having higher molecular weights are the more desirable. The plastic is molded in the conventional manner and the polystyrene itself is a well known commercial product available from a nurn ber of different manufacturers. The polyethylene is also a weli know-n commercial plastic and preferably is ofthe type which contains at least one thousand CH2 groups or more to the molecule.

The side walls of the receptacle are of such a construction as to provide an inwardly directed peripheral shoulder at its lower inside surface. This structure inipa-rts suflicient strength to the said receptacle to enable it to resist distortion due to pressure differentials created within the container as by condensation of vapors and gases therein as well as by reason of the weight and character of the contents and of outside forcescoming in contact with the container. This novel side wall structure, in addition to imparting the above advantages, has further beneficial characteristics in that the inwardly extending inner shoulder aids in the stacking of the container bodies so that they may be nested in a manner which will allow them to be economically shipped and stored for use.

The containers may be of any desirable shape but preferably are rectangular, as illustrated, thus providing for maximum utilization of space when a multitude of them are placed in the food locker. In addition, it should be noted that the top edges of the body are outwardly offset thus imparting a maximum sealing effect when these edges are received by the peripheral sealing groove embodied in the closure.

In the drawing:

Figure l is a side view of the container with cover in place;

Figure 2 is a top view of the container body;

Figure 3 is a bottom view of the same and Figure 4 is a vertical cross-section through the container, and also showing in dot and dash lines a second container to illustrate stacking.

Referring to Figure 1, the container is provided with a body, indicated in its entirety as 10, formed of poly styrene which is transparent and relatively stiff, i. e., flexible but diflicultly distortable. The walls of the receptacle 10 possess sufiicient strength to resist distortion due to pressure differentials created within the container as by condensation of vapors and gases therein, as well as by reason of other destructive forces coming in contact with the same. The primary source for this greatly enhanced strength is an inwardly extending step 12 which is created by the variation in thickness of the side walls in their lower portion. A careful examination of the figures will indicate that this step is particularly thick in the radius of the corners thereby giving even greater strength and eliminating breakage or cracks that may occur between the corners and the bottom of the container.

The container 10 is closed by a cover 14, made of polyethylene, as illustrated in Figure 1 and disclosed in the aforementioned Patent No. 2,606,586. This material is flexible, rubbery and opaque and when it is used with polystyrene adhesive forces tend to produce a seal in a highly desirable manner.

Referring to Figures 2 and 4, I find that it is essential that the thickness of the side walls of the container be of unequal size, as shown, each of said thicknesses being substantially uniform peripherally. In this way, the step 12, heretofore referred to, is formed and imparts characteristics much like a structural rib utilized in buildings. The container will thus support tremendous weights imposed upon it without cracking or fracturing and notwithstanding changes in temperature conditions or the character of its contents. This is of tremendous importance in food lockers and enables the receptacle to have a much greater utility. Also, the use of polystyrene is more desirable than glass because the former, if it fractures or breaks, will not shatter contrary to the characteristics of glass.

At its upper end the wall of the container is offset as shown at 16 and the offset marginal portion 18 at the top of the container forms the sealing edge for engagement with the closure 14. At its lower end, the side wall is provided with the inwardly directed peripheral shoulder 12 and the thickness of the container side wall above this shoulder is reduced, as shown at 20, to the top 22. The thickness of the wall below the reduced area 20 must also be substantially uniform peripherally and preferably longitudinally. As heretofore set forth, the purpose of the reduced portion 20 becomes apparent when it is noted that a structural shoulder is produced. In addition, reference to Figure 4, where the containers are shown in nested relation, illustrates the further advantage imparted by this shoulder, to wit, the economy in shipping and stock storing.

As has been observed, the body 10 is made of polystyrene plastic of such character that it will not distort under various conditions of use whereas the closure 14 is made of polyethylene which is relatively distortable. It would not be possible to make the body of the polyethylene because pressure differentials, weight of super imposed filled containers or other articles, as well as the weight of the contents, would cause distortion of such a body which would he undesirable. Likewise, it would not be possible to have a polystyrene body and a polystyrene cover since the tight adhesive sealing relation described above would be lost. By making the cover of distortable material it may advantageously be used to take care of differences in the coeificient of expansion and contraction between the respective plastic materials. It also assures that the container will be equally satisfactory where gas pressures are created and where a vacuum is produced by condensation of gases within the container.

The plastic materials are odorless, tasteless, moistureresistant and inert with respect to most foods, medicines and chemicals, and have a long life.

The novel principles of this invention are broader than the specific embodiments recited above and rather than unduly extend this disclosure by attempting to list all the numerous modifications which have been conceived and reduced to practice during the course of this development, these novel features are defined in the following claim.

I claim:

A generally box-like container having a plastic body, said body comprising a bottom and outwardly tapering side walls extending upwardly therefrom, said side walls being outwardly offset at the top edges thereof and otherwise being externally smooth and uninterrupted, the thickness of said side walls being uniform throughout the greater portion thereof and enlarged to define an inwardly directed, continuous strengthening shoulder adjacent the bottom of said side Walls, the internal surface of said container side walls from said shoulder to said offset edges being of substantially the same size as the external surface of said side Walls from the bottom thereof upward to a distance equivalent to the distance between said shoulder and said offset edges to permit a second like container body to be nested within said first named container body with the lower edges of said second container engaging the shoulder of said first container and the side walls of said second container being embraced by the side walls of said first container throughout the entire length of said latter walls between said shoulder and said offset edges, to thereby prevent any lateral relative movement between'said containers and also to prevent any wedging of said containers while nested.

References Cited in the file of this patent UNITED STATES PATENTS 1,587,167 Marsden June 1, 1926 1,674,475 Loomis June 19, 1928 2,088,181 Swift July 27, 1937 2,487,400 Tupper Nov. 8, 1949 2,606,586 Hill Aug. 12, 1952 2,614,727 Robinson Oct. 21, 1952

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