Insulated container, method of fabricating same and apparatus for fabricating

This application is related to, and claims priority from, U.S. Provisional Application Ser. No. 60/671,798 and Ser. No. 60/672,195, both filed on Apr. 15, 2005. The disclosure of each of these provisional applications is, in its entirety, incorporated herein by reference.

The invention generally relates to containers. It relates particularly to insulated containers for hot drinks or the like, a method of fabricating such containers and an apparatus for fabrication of such containers.

There are many examples in the prior art of hand-held, insulated containers for hot liquids such as coffee, tea, soups and the like. Examples may be found in U.S. Pat. No. 2,266,828, U.S. Pat. No. 4,007,670, U.S. Pat. No. 5,145,107, U.S. Pat. No. 5,460,323, U.S. Pat. No. 5,524,817, U.S. Pat. No. 5,685,480, and U.S. Pat. No. 6,663,926. Each of the containers disclosed there includes an inner cup and an outer shell separated by an air gap. In modern containers of this type, the cup is fabricated of thin paperboard coated inside with a polyethylene resin or the like. The inner cup and outer shell are fastened together by gluing them in strategic locations at top and bottom or, in some recent instances, by heat sealing them together. The air gap between the cup body wall and the shell is conventionally maintained by spacers of varying configuration.

It is an object of the present invention to provide an insulated container having an improved inner cup and outer shell construction.

It is another object to provide an improved method of fabricating an insulated container.

It is another object to provide an improved method of bonding the cup and shell together in an insulated container.

It is still another object to provide an apparatus for fabricating an improved insulated container.

The foregoing and other objects are realized in accord with the present invention by providing an insulated container wherein a thermo-sealable plastic coating is provided on at least one of the inside of the cup shell or the outside of the cup body. The coating is heated and the cup body is seated within the shell, after which at least one bonding spot and/or bonding area for fastening the shell to the cup body with the plastic coating is formed within a corresponding contact path. This “contact path” is generally a virtual contact path where the outer surface of the cup body and inner surface of the shell may be in contact when the cup is seated within the shell. However, it is not necessary that there be actual contact between the corresponding walls of shell and cup body along all of their common circumferences. The contact path may only extend partially along the common circumferences, and within this contact path corresponding bonding spots and/or bonding areas are located. These spots or areas are locally formed by a method wherein shell and cup wall are pressed together at one or more of such bonding spots and/or bonding areas within said contact path. Because the corresponding thermo-sealable plastic coating is melted prior to inserting the cup in the shell, the cup and shell are bonded in the corresponding bonding spots and/or bonding areas by hardening of this coating as it cools.

In the alternative, it is also possible that the bonding path be a continuous, annular path which completely encircles the cup body and shell. Such a path may also have a certain width in a vertical direction, i.e., perpendicular to the corresponding circumferential direction.

According to the invention, it is possible to use one bonding spot or bonding area because the bonding is only used to prevent the inner cup from separating during handling of the container for assembly, packaging, nesting or the like. After a corresponding hot drink or the like is poured into the container, the inner cup will be retained within the shell by the weight of the drink, so that a corresponding bonding spot or bonding area need only provide a minimal fastening force.

According to the invention it is also possible to more securely fasten cup body and shell to each other by, for example, providing a number of bonding spots and/or bonding areas formed along the contact path, all separated from each other by bond free areas in the contact path. Moreover, the bonding spots and/or bonding areas may be arranged side-by-side and separated from each other in horizontal and/or vertical directions within the contact path. This means that single bonding spots or bonding areas are arranged in horizontal or vertical directions, or that a group of such bonding spots or bonding areas is formed with each group arranged in a vertical direction, and that such groups are then arranged side-by-side, circumferentially of the container.

It is also possible to provide that corresponding bonding spots and/or bonding areas are unevenly distributed in a circumferential direction. However, to improve the assembly of the container, and also the corresponding method of fabricating, it may be advantageous if the corresponding spots or areas are evenly distributed.

The insulated container of the invention has a gap between the cup wall and the shell wall in a lower section of the container. Generally the air gap should be maintained without any heat transferring connections. Consequently, it is advantageous to form the corresponding contact path between an annular upper wall section of the cup body and an upper, essentially cylindrical section of the shell. In this part of the container, a gap is unnecessary because the contact path is disposed higher than the level of the beverage in the container.

It is preferable to arrange the bonding spots and/or bonding areas immediately adjacent to the lower edge of an annular upper wall section of the cup body. The lower edge is preferably defined by an annular shoulder. Below this shoulder is where the air gap begins.

Different materials may be used for the shell and the cup, and at least one of those components may be made of plastic. For recycling reasons, it is also possible that the cup and/or the shell may be made of paperboard. To obtain sufficient imperviousness to hot fluid, the paperboard for forming the cup is preferably coated with the above mentioned polyethylene resin or the like. The paperboard can also be provided with a thermo-sealable plastic coating on the outside of the cup wall, the inside of the shell wall or on both of those walls.

The corresponding bonding spots or bonding areas may also have different shapes. For example, bonding spots may be circular, rectangular or have other cross-sections. The corresponding bonding areas may also be in the form of short stripes and the stripes may be horizontally arranged or may also be inclined with respect to circumferential direction.

The corresponding plastic coating may be melted by local heating only. However, it is also possible that an annular strip of plastic coating be heated along its entire length.