US2784901A - End closure for container - Google Patents

Description

March 12, 1957 l. L. WILCOX END CLOSURE FOR CONTAINER Filed Nov. 6, 1952 INVENTOR. L. Wu. :0 X

w ggw v United States Patent END CLOSURE FOR CONTAINER Isaac L. Wilcox, Fulton, N. Y., assignor to Oswego Falls Corporation, Fulton, N. Y., a corporation of New York Application November 6, 1952, Serial No. 319,037

3 Claims. (Cl. 229-43) This invention relates to containers formed of fibrous sheet material, such as paperboard, and has particular reference to a novel end closure structure for such containers.

The primary object of the invention is to provide a container end closure structure which may be formed quickly and economically, and which is particularly strong and leak-proof.

A further important object of the invention is to provide a container end closure structure which forms an insulated bottom for the container, making it particuiarly useful for hot beverages.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is a perspective view of a container embodying the end closure of the invention.

Figure 2 is a cross section through the container taken along line 2-2 of Figure 1.

Figure 3 is a vertical section taken along line 3-3 of Figure 2, illustrating the details of the end closure structure.

Figure 4 is an enlarged section taken through the inner end closure member.

The body of the container is of tubular formation, substantially square in cross section, and may be provided with a yieldable top'flange of conventional design for the reception of a slip cover 12, as shown. The bottom closure structure, indicated generally at 14, comprises an inner end closure member 16 and an outer end closure member 18. The inner closure member 16 is a substantially square blank, the peripheral marginal portion of which is folded upon itself to form an inwardly extending flange 20 in contact with the outer or bottom surface of the blank. In its folded form, member 16 is so dimensioned as to slidably fit within the container body 10 and is positioned horizontally therein, with the outer surface of the flange 20 being coplanar with the edges of the container end, as shown in Figure 3.

The outer end closure member 18 is also formed from a substantially square blank, the latter being of greater area than the cross sectional area of the container body 19. This blank is positioned in contact with the outer surface of flange 20 and the edges of the container end so that its center is in registry with the longitudinal axis of the container body. The extending marginal portions of the blank are folded upwardly into engagement with the outer walls of the end portion of the container body forming an external flange or rim 22 surrounding the body. The inner surface of member 18 is coated with impervious adhesive material which is preferably of the heat sealing type, such as Vinylite, or, if desired, both inner and outer end closure members 16 and 18, and the end portion of container body 10 may be so coated. This coating permits the engaging surfaces of the flange 20 and member 18 to be sealed together as at 24, and the engaging surfaces of the member 18 and container body end portion to be sealed together as at 26, thereby forming a strong, liquid-tight end closure.

In assembling a large number of such end closures, a container body 10 is usually mounted upon a movable mandrel and conveyed to a station where an inner end closure member 16 is positioned in the container against the end of the mandrel, the flange 20 having been previously formed on the member. The body 10 and end closure member are then moved into registry with a supply of outer end closure blanks, and one of these is positioned against the flange 20 and edges of the container end and its extending marginal portion folded into engagement with the walls of the container body to form the member 18. Thereafter, seals 24 and 26 are completed upon the application of heat and pressure to the outer surface of member 18.

The end closure suucture described provides an insulated liquid-tight container bottom, the insulating feature thereof being obtained by the dead. air space 28 in the enclosed, sealed chamber formed by the flange 20 and inner and outer end closure members 16 and 18. In addition, it will be noted that no uncoated or raw edges of the fibrous material comprising the container are in a position to contact a liquid contained therein. Ordinarily, the sheets of fibrous material from which the containers are made are coated on both surfaces with a protective moisture resistant substance. However, when the individual container elements, as for example the inner and outer end closure members 16 and 18, are stamped or cut from a large sheet, the edges of the elements are uncoated, or in a raw state. Obviously, if the edges were in contact with the liquid in the container, the liquid would soon be absorbed therethrough and diminish the utility of the container. In the illusstrated construction, the seal 24 between the flange 20 and inner surface of member 18 prevents any liquid from coming into contact with the uncoated peripheral edges of the inner end closure member 16. It will also be observed that the construction of the invention provides a double liquid-tight seal, that is, seals 24 and 26, so that if liquid in the container should happen to leak through the seal 24, due to some defect therein, it would still have to work its way up through seal 28 to escape from the bottom of the container.

From the foregoing description, it will be apparent that the invention provides a novel container end closure structure which may be quickly and economically formed and which is particularly strong and leak-proof. In addition, the end closure structure provides an insulated bottom arrangement for the container so that the latter is particularly well suited for hot beverages.

What I claim is:

1. An end closure for a container having a substantially tubular container body comprising an inner end closure member positioned in said body adjacent one end thereof, the marginal portion of said closure member being folded upon itself to form an inwardly extending flange contacting the bottom surface thereof, an outer end closure member positioned against said flange, the marginal portion of said outer closure member being folded to engage the outer surface of the end portion of said container body, and means to seal said outer closure member to said flange and container body in liquid-tight relation.

2. An end closure for a tubular container of substantially square cross-section comprising a substantially square inner end closure member having its marginal portion folded upon itself to form an inwardly extending flange, said folded end closure being dimensioned to slidably fit within said container and being positioned therein "with its flange coplanar with one end thereof, a substantially square outer end closure member positioned against said flange and the edge of said container end, said 'outer closure member "being of greater area than the cross-sectional area of said container and having -'its extending marginal portion folded to engage the outer surfaces of the container walls adjacent said container end, and means on said outer end closure to seal 'it to said flange and "container walls upon the application of heat and pressure.

3. An end closure as defined in claim 2, wherein said flange and inner and outer end closure members form 'an'en'closed dead air space within said closure.

References Cited in the file of thispatent UNITED STATES PATENTS

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