The present invention generally provides an insulating vessel for beverages. The vessel has an outsert and a insert. The insert is positioned within the cavity of the outsert. In one embodiment the insert has a plurality of insulating members that are spaced from an inner surface of the outsert to define a series of air gaps between an outer surface of the insulating members and the inner surface of the outsert. In another embodiment, the insert and outsert have generally conical side walls with substantially the same taper angle so as to be in a friction lock relationship with one another.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

TECHNICAL FIELD

The present invention relates generally to a disposable container, and more specifically to a thermally insulated drinking cup having an outsert and an insert.

BACKGROUND OF THE INVENTION

Various methods, containers and auxiliary devices for providing insulation to a container to keep the contents of a container warm/cold and to lessen the effects of the transfer of heat/cold to a user's hand are well known in the art. While such insulating containers and jackets according to the prior art provide a number of advantageous features, they nevertheless have certain limitations. The present invention seeks to overcome certain of these limitations and other drawbacks of the prior art, and to provide new features not heretofore available. A full discussion of the features and advantages of the present invention is deferred to the following detailed description, which proceeds with reference to the accompanying drawings.

SUMMARY OF THE INVENTION

The present invention generally provides an insulating vessel for beverages or other foods. In one embodiment the insulating vessel comprises an insert and a separate outsert. The insert has a sidewall and a bottom wall defining a cavity, and the insert is positioned within a cavity of the outsert. The sidewall of the insert has a plurality of alternating rib members and insulating members. The insulating members are spaced a distance from an inner surface of the outsert to define a series of air gaps between an outer surface of the insulating members and the inner surface of the outsert.

According to another embodiment, the insulating members have a generally arcuate shape comprised of a convex outer surface and a concave inner surface. The convex outer surface faces generally radially toward a center of the cavity of the container, and the concave inner surface faces generally radially toward the inner surface of the outsert.

According to another embodiment, the insulating members have a generally flat wall portion extending between the rib members and vertically about the sidewall of the insert. Thus, a plurality of air gaps are provided between the inner surface of the outsert flat wall portion of the insulating members.

According to another embodiment, the outsert is made of a paper material, and the insert is made of a plastic material. Further, in one embodiment the insert is made of a polymer foam material.

According to another embodiment, the insulating vessel comprises a paperboard outsert having a first end, a second end, and a generally conical side wall therebetween, and a separate plastic insert nested within the outsert. The insert has a first end, a generally conical side wall and a bottom wall at a second end of the outsert which closes a bottom of the insert. In one embodiment the generally conical side walls of the insert and the outsert have substantially the same taper angle so as to be in a friction lock relationship with one another.

DETAILED DESCRIPTION

While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated. Particularly, the insulated container is described and shown herein as a cup for containing hot liquid, such as coffee, tea, etc. However, it should be understood that the present invention may take the form of many different types of vessels or containers used for holding heated liquids, including but not limited to beverages, soups, stews, chili, etc. Additionally, a person skilled in the art would readily recognize that the thermally insulated vessel or container of the present invention may also be used to insulate a cup holder's hand from cold contents, such as an ice-cold beverage.

Referring now in detail to the Figures, and initially toFIGS. 1 and 2, there is shown one embodiment of an insulated vessel or container10. The container10is generally comprised of an outsert12and an insert14. The container10has a cavity16to hold the beverages placed therein, and to insulate them from the cup holder's hand. Thus, the container10provides insulation properties and gives the appearance of a single cup or food/beverage container10.

The Outsert12:

In one embodiment, as shown inFIG. 3, the outsert12has a sloping or frustoconically configured sidewall18, and a bottom wall20defining an outsert cavity19. Generally, the paper outsert12is made by forming a paperboard container having a side seam, and connecting the bottom wall20to the sidewall18of the outsert12. The sidewall18has an inner surface21and an outer surface23. Additionally, the sidewall18has a first end22and a second end24. The bottom wall20of the outsert12is generally positioned a distance proximal the second end24of the sidewall18. This allows the bottom wall20to be recessed upward from second end24of the outsert12. Accordingly, in a preferred embodiment the height (H1) of the sidewall18from the first end22to the bottom wall20is less than the distance of the sidewall18from the first end22to the second end24. Alternatively, as shown inFIG. 19A, the bottom wall20may extend adjacent the second end24of the sidewall18of the outsert12, and, as shown inFIG. 19B, the sidewall18of the outsert12is folded over and connected to a disc-shaped bottom wall20. As a further alternative shown inFIG. 20, the outsert12may have no bottom wall. This style of outsert12would be akin to a sleeve. In such an embodiment, the insert14would be attached to either the inner surface21of the outsert12, or to the rim26of the outsert12as detailed below. It is also understood that another alternative to the embodiment ofFIG. 3is possible. In such an embodiment the second end24of the sidewall18of the outsert12that is connected to the skirt portion of the bottom wall20may be bent radially inward and substantially parallel to the bottom wall20to reduce the stack height of the container10. Accordingly, it is understood that the formation of the outsert12, including the connection between the sidewall18and the bottom wall20, if any, may be accomplished in a variety of methods without departing from the scope of the present invention.

Further, the outsert12may or may not have a rim26associated therewith. In the embodiments shown inFIGS. 1-3and10, the outsert12terminates at the first end22of the sidewall18and has no curled rim extending therefrom. In alternative embodiments, as shown inFIGS. 5-6,11-17and19-20, the outsert12has an outwardly extending rim26depending from the first end22of the sidewall18of the outsert12.

As explained above, the sidewall18of one embodiment of the outsert12is frustoconical in shape. In alternate embodiments, however, it is understood that the sidewall may have other geometric configurations, including being straight or substantially perpendicular to the bottom wall. Accordingly, the inner surface21of the sidewall18of the outsert12has an inner diameter (IDOUTSERT) associated therewith. Where the sidewall18of the outsert12is frustoconically shaped or sloped in geometry, the inner diameter (IDOUTSERT) of the outsert12decreases from the first end22of the outsert12to the second end24of the outsert12. In a preferred embodiment, the sidewall18of the outsert12is provided at a sidewall taper angle (α). In one example of a 20 oz. container10, the outside sidewall taper angle (α) of the outsert12is approximately 5° 55′ 0″ with respect to a centerline of the outsert12.

In a preferred embodiment, the outsert12is made from a paper substrate. Further, in a preferred embodiment having a bottom wall20the outsert12is made of a two-piece construction. As such, the sidewall18is one component and the bottom wall20is a separate component that is joined to the sidewall18. It is understood, however, that the outsert12may be made of a one-piece component. Further, it is understood that the outsert12may be made of materials other than paper without departing from the scope of the present invention. Specifically, the outsert12may be made of a plastic material, a pulp molded material, a foam material including a starch-based foam material, or other materials suitable for forming an outsert12.

In the embodiment illustrated inFIGS. 1-3, the paper stock for the sidewall18of the outsert12is approximately 0.0113″ thick normal sizing low density uncoated paper, and the paper stock for the bottom wall20of the outsert12is approximately 0.0093″ thick normal sizing medium density uncoated paper. In an alternate embodiment, such as shown inFIGS. 5-20, the paper stock for the sidewall18of the outsert12is approximately 0.016″ thick, and the paper stock for the bottom wall20of the outsert12is approximately 0.012″. It is anticipated, however, that the stock thickness of the paper for the outsert12, and most especially for the sidewalls18, may be reduced without detrimentally affecting the rigidity of the overall container10. Additionally, if desired, the paper stock may also be thicker than that identified in the embodiment above. Further, one of ordinary skill in the art would readily understand that variations in the sizing, coating, density, etc. of the stock paper may be employed without departing from the scope of the present invention. Using a paper material for the outsert12of the container10of the present invention provides several advantages: the outsert12can be inexpensively produced on high-speed conventional cup forming equipment; the paper can be preprinted; the printing can extend the full length or height (H) of the sidewall18(i.e., from the first end22of the sidewall18to the second end24of the sidewall18); and, the stiffness and rigidity of the outsert12is maintained.

As explained above, if paper is utilized as the material for the outsert12, the paper may or may not have a coating. In one such embodiment, the paper outsert12does not have a coating thereon. Such an outsert12may be formed by a cold-seal forming process at extremely high speeds on conventional cup-forming equipment. Because this type of outsert12is manufactured without a coating and at extremely high speeds, it is generally less expensive to manufacture. In an alternate embodiment, however, the paper material of the outsert12may be coated with a coating. Various coatings include wax, polymer based coatings such as a polyethylene or polypropylene based coating, coatings that are not polymer based, environmentally-friendly based coatings such as biodegradable coatings, non-oil based resins, etc. Naturally, these and other coatings may be used and still fall within the scope of the present invention. If a coating is utilized, it may be applied to one or both of the inner surface21and/or the outer surface23of the outsert12. One purpose of using a coated paper-stock material is to provide an insulation barrier against the transfer of heat through the side wall18or, to a lesser extent, through the bottom wall20of the outsert12. An additional purpose of the coated paper-stock material is for adhesion or bonding purposes during manufacturing of the outsert12.

The Insert14:

A variety of inserts14may be utilized with the various embodiments of the outsert12described above to form the overall container10. The insert14generally comprises a vessel for holding the heated or cooled food/beverage or other item placed in the container10. In a preferred embodiment, the insert14is a vessel that provides insulative properties. Like the outsert12, the insert14has a sidewall30and a bottom wall32defining an insert cavity33. In the finished container10, the insert cavity33is the container cavity16of the overall container10. Additionally, the insert14may be a vessel that has sealed seams, or it may be a seamless vessel.

Various embodiments of the insert14for the container10are shown in the Figures. Generally, the sidewall30of the insert14has a first end38and a second end40, an inner surface42, an outer surface44and an outside diameter (ODINSERT). In one embodiment, such as shown inFIGS. 4 and 9, the bottom wall32of the insert14extends from the second end40of the insert14. The bottom wall32may be substantially flat, or it may be slightly domed as shown in theFIG. 4. Additionally, the insert14has a height (H2) from the first end38to the second end40thereof. In the embodiment shown inFIGS. 1-4, the height (H2) of the insert14is generally less than the height (H1) of the outsert12. Alternatively, the height (H2) of the insert14may be substantially equal to the height (H1) of the outsert12.

In the embodiment ofFIG. 4, like the sidewall18of the outsert12, the sidewall30of this embodiment of the insert14, or at least a portion of the sidewall30of this embodiment of the insert14, is also generally sloping or frustoconical in shape. In a preferred embodiment, the sidewall30of the insert14is provided at a sidewall taper angle (β). In one example of a 20 oz. container10, the outside sidewall taper angle (β) is approximately 5° 59′ 32″ with respect to a centerline of the insert14.

Additionally, in the embodiment shown inFIGS. 1-4, the sidewall taper angle (β) of the insert14is substantially identical to the sidewall taper angle (α) of the outsert12. Because of manufacturing constraints, however, the sidewall taper angle (α) of the insert14may not be exactly identical to the sidewall taper angle (β) of the outsert12. For example, if the insert14is made of a foam material, the expansion of the foam material during manufacture thereof is only controllable within certain limits. Thus, to account for variations in either the insert14or the outsert12, in a preferred embodiment the sidewall taper angle (α) of the insert14is slightly dissimilar from the sidewall taper angle (β) of the outsert12(i.e., in one example α equals 5°55′ 0″, and β equals 5° 59′ 32″.

Alternatively, in the embodiment ofFIGS. 7-11the sidewall30of the insert14is not made of a substantially straight frustoconical wall. Rather, the sidewall30of the insert14has an insulation portion45comprised of a series of vertical ribs46alternating with a series of vertical arcuate insulating members48. The ribs46generally provide increased rigidity to the insert14, as well as a termination point for the air gaps82identified below.

The vertical arcuate insulating members48extend radially inward from the outside diameter (ODINSERT) of the insert14. Typically, in the preferred embodiment the individual radius of each arcuate member (RAM) about a specific horizontal plane of the insert14is uniform, however the radius of the arcuate members (RAM) about a specific horizontal plane may, or may not, decrease as the horizontal planes extend from the first end38of the insert14to the second end40of the insert14. If, however, the sidewall30of the insert14is not frustoconical in shape, the radius of the arcuate members (RAM) about a specific horizontal plane may be constant for each individual horizontal plane as the horizontal planes extend from the first end38of the insert14to the second end40of the insert14. The preferred embodiment of the insert14cross-sectional geometry, however, seeks to maximize the sidewall30strength of the insert14.

Vertical ribs46and vertical arcuate insulating members48are disclosed for this embodiment, however, it is understood that the geometry and positioning of the ribs and insulating members may be varied without departing from the scope of the present invention. Thus, the ribs and insulating members may be any organized or random shape, including but not limited to horizontal, sinusoidal, vertical or angular. In an alternate embodiment described below the insulating members48comprise flats or facets47. Further, as discussed below, while the individual positioning of the ribs and insulating members on the insert is not critical, the positioning of these members when the insert14is combined with the outsert12is more important.

As shown in theFIG. 9, the sidewall30of one embodiment of the insert14is made of several different areas. First, a circumferential straight-wall ring portion50of the insert14is provided adjacent the first end38of the insert14. Next, a transition area52is provided between the straight-wall ring portion50of the insert14and the insulation portion45of the insert14. In this embodiment the transition area52provides a chamfered or beveled portion to connect to a top54of the arcuate insulating members48. It is understood that in different embodiments the insert14may not have a circumferential straight-wall ring portion50and/or a transition area52. Instead, the insulation portion45of the insert14may extend to the first end38of the insert14.

A necked-down or stepped portion56of the insert is adjacent the bottom32of the insulating portion45of the insert14. As is detailed more fully below, the necked-down portion56assists in nesting or stacking of the containers10. If nesting or stacking of the containers10is not a concern, the necked-down portion56of the insert14may be eliminated. Generally, the necked-down portion56comprises a shoulder60and a smaller circumferential straight-wall ring portion62. The smaller circumferential straight-wall ring portion62ends adjacent the bottom wall32of the insert14. A first radius64joins the shoulder60to the sidewall30; a second radius66joins the shoulder60to the straight-wall ring portion62; and, a third radius68joins the straight-wall ring portion62to the bottom wall32.

As explained above, the insert14has an outside diameter (ODINSERT). In such an embodiment the outside diameter (ODINSERT) of this insert14generally refers to the outside diameter (ODINSERT) of the vertical ribs46. As explained above, the sidewall30of the insert14is generally sloping or frustoconical in shape. Accordingly, similar to the inner diameter (IDOUTSERT) of the inner surface21of the outsert12, the outside diameter (ODINSERT) of the insert14decreases from the first end38of the insert14to the second end40of the insert14.

The insert14also has an inner diameter (IDINSERT) that generally refers to the inside diameter (IDINSERT) of the adjacent apexes70of the arcuate insulating members48. The arcuate insulating members48are a portion of the sidewall30, and thus while formed of arcuate members they nevertheless have a sloping angle to them. Accordingly, similar to the inner and outer diameters discussed above, the insert inner diameter (IDINSERT) also decreases from the first end38of the insert14to the second end40of the insert14.

Another alternative embodiment of the insert14is shown inFIGS. 21 and 22. In this embodiment the sidewall30of the insert14is not made of a substantially straight frustoconical wall. Rather, like the embodiment above, the sidewall30of the insert14has an insulation portion45comprised of a series of flats or facets47, instead of vertical arcuate insulating members48. In a preferred example of this embodiment, the flats47are vertically aligned and are adjoining at vertical ribs46, however, one of ordinary skill in the art would understand that they do not need to be adjoining and could have arcuate or other shaped portions therebetween. The flats47and ribs46similarly assist in providing increased rigidity to the insert14, as well as a providing an area for the air gaps82identified below.

In one embodiment of the insert14with flats47on the sidewall30thereof, twelve flats47are provided. It is understood, however, that fewer or more flats47may be provided on the sidewall30of the insert14. The flats47are generally flat walled members. In such an embodiment the insert14has an outside diameter (ODINSERT) that is measured from the vertical ribs46of the insert14. Similarly, the insert14has an inner diameter (IDINSERT) that generally refers to the inside diameter of the adjacent centers49of the flats47. The flat47style of insulating members48are a portion of the sidewall30, and thus while formed of flats they nevertheless have a sloping angle to them. Accordingly, similar to the inner and outer diameters discussed above, the insert inner diameter (IDINSERT) and outer diameter (ODINSERT) generally decrease from the first end38of the insert14to the second end40of the insert14.

Referring toFIG. 21, the sidewall30of this embodiment of the insert14is also made of several different areas. First, a circumferential straight-wall ring portion50of the insert14is provided adjacent the first end38of the insert14. Next, a transition area52is provided between the straight-wall ring portion50of the insert14and the insulation portion45of the insert14. In this embodiment the transition area52provides a transition to a top54of the flat47insulating members48. Finally, a stepped or necked-down portion56of the sidewall30of the insert14is provided adjacent the second end40of the insert14. As explained above, the necked-down portion56generally assists in nesting or stacking of the containers10. If nesting or stacking of the containers10is not a concern, the necked-down portion56of the insert14may be eliminated. It is also understood that the stepped down portion56may comprise intermittent shoulders60or protrusions extending into the cavity of the insert14, such as for example three equally spaced shoulders, or it may comprise a continuous ring about the interior of the sidewall30thereof.

Referring to the Figures, one embodiment of the insert14has a rim or lip86. In a preferred embodiment of this insert14, the rim86is formed as part of the insert14, and most preferably is formed as an outwardly formed or outwardly rolled member thereof. As explained below, in a preferred embodiment of the container10the insert14has a rim86and the outsert12does not (see for exampleFIGS. 2 and 10). Alternate embodiments are possible, however, where the insert14has no rim and the outsert12has a rim26, and where both the insert14and the outsert12have rims (see for exampleFIG. 11). In the latter embodiment where both the insert14and the outsert12have rims, the rim of the container10may be formed by rolling the rim of the insert14and the outsert12together to form a unified rim for the container10, or by rolling the rim86of the insert14around the rim26of the insert12.

The insert14may be made of various materials. In the embodiment ofFIGS. 1-4and21-22, the insert14is preferably made of a thermoplastic material. Most preferable the material is a foam material comprising polystyrene, however, the material be, but is not limited to, polypropylene, polyethylene, polyester, polystyrene, polycarbonate, nylon, acetate, polyvinyl chloride, saran, other polymer blends, biodegradable materials, paper, etc. By selecting the desired plastic or non-polymer material and further selecting the appropriate properties for the selected material, the insert14can be formed of a material that is tailored to the product end use. In one particular embodiment, such as the insert14ofFIGS. 1-4and21-22is made of a thermoformed polystyrene foam. Thermoforming is an inexpensive forming process used to rapidly produce high volumes of insert14. It is understood, however, that a variety of other forming methods for creating the insert, may be utilized without departing from the scope of the present invention. For example, in another embodiment of the insert14, such as that shown inFIGS. 5-9, the insert14is made of a plastic material, and most preferable polypropylene, however, the material may be, but is not limited to, polyethylene, polyester, polystyrene, polycarbonate, nylon, acetate, polyvinyl chloride, saran, other polymer blends, biodegradable materials, etc. As in the example above, the preferred method of manufacture for the insert14ofFIGS. 5-9is via a thermoforming process which is different from the above-type of thermoforming process. In this example, the specific type of thermoforming process begins with a thin sheet or web of material. The sheet or web is heated to a temperature suitable for thermoforming the web, in the range of from about 110° C. to about 200° C. for the above-mentioned materials, and is then fed into a conventional forming machine with the aid of which the thermoforming process takes place under applied vacuum conditions. A mold cavity is used to impart a particular design into the sidewall of the insert14as the plastic material is drawn into the mold using vacuum pressure on one side and a positive pressure on the opposite side of the material. The processing time for a normal thermoforming operation of this type is typically between 1 and 20 seconds.

Methods of Manufacturing Various Embodiments of the Insulating Container10:

In one embodiment, such as that shown inFIGS. 5-9, to create the container10an insert14and an outsert12are separately formed, and the insert14is placed in the outsert12. In one example, the insert14is made of a thermoforming process as described above. This insert14generally has a wall thickness72associated therewith. In a preferred embodiment, the wall thickness72of this type of insert14is substantially equal about each member of the insert14. As such, the entire sidewall30of the insert, including the vertical ribs46and the vertical arcuate insulating members48, and the bottom wall32of the insert have a substantially equal thickness. With the thermoforming process described above, the wall thickness72is approximately 0.003″ to 0.010″, however different thicknesses may be used. It is understood that to attain various qualities of the container10, the insert14and outsert12may be manufactured of different materials, thicknesses and geometry variations.

When a thermoforming process is utilized in such an embodiment, the stock material is usually provided in sheet form. During the forming process of the insert14, a lip35thereof is created. In a thermoforming process the lip35has a flange74. As is understood by one of ordinary skill in the art, the flange74is merely a remnant of the thermoforming process. Further, while the flange74is illustrated in the figures, it is typically trimmed off or minimized by design prior to joining the insert14to the outsert12.

In this embodiment, when the insert14is placed in the outsert12, the bottom wall32of the insert14generally contacts and rests on the bottom wall20of the outsert12. Also, the outer surface44of the circumferential straight-wall ring portion50of the insert14contacts the inner surface21of the sidewall18of the outsert12. The necked-down portion56(i.e., the shoulder60and the smaller circumferential straight-wall ring portion62), however, generally does not contact either the bottom wall20or the inner surface21of the sidewall18of the outsert12. Accordingly, due to the geometry of the necked-down portion56, an air gap80is provided between the necked-down portion56of the insert14and the adjoining outsert12.

Further, a portion of the outer surface44of the insert14generally contacts the inner surface21of the outsert12, and a portion of the outer surface44of the insert generally does not contact the inner surface21of the outsert12. More specifically, the outer surface44of the ribs46contacts the inner surface21of the sidewall18of the outsert12, but the outer surface44of the arcuate insulating members48does not contact the inner surface21of the sidewall18of the outsert12. Instead, a series of air gaps82are provided between each radially inward arcuate insulating member48and the inner surface21of the sidewall18of the outsert12. The air gaps82generally terminate at the ribs46because the ribs generally contact the inner surface21of the sidewall18of the outsert12. Further, in the preferred embodiment where the ribs46and the arcuate insulating members48are vertical, the air gaps82also terminate at generally the intersection of the transition area52and the straight-wall ring portion50adjacent generally the first end38of the insert14. The air gaps82may also terminate adjacent a bottom of the arcuate insulating members48. However, in the preferred embodiment the air in the air gaps82is in fluid communication with the air in the gap80provided between the necked-down portion56of the insert14and the adjoining outsert12. Accordingly, in the preferred embodiment the air gaps82are in fluid communication.

As shown in the figures, the insulating members48of this embodiment have a generally arcuate shape, wherein the concave portion of the arcuate shape faces the sidewall18of the outsert12. Accordingly, the convex shape faces radially toward the insert cavity33. Such a shape is not a matter of mere design choice. Through testing it has been found that the convex inward arcuate shape of the insulating members48provides increased rigidity for the insert14of this type construction and material, such that when beverages or other items are placed in the cavity33of the container10the insulating members48do not collapse. If the insulating members48collapsed, the outer surface44of the insulating members48would come in contact with the inner surface21of the outsert12, thereby at least partially defeating the thermally insulating properties of the present invention. Nevertheless, while the arcuate shape of the insulating members48provides the container10with a good insulating member, it is understood that other shapes and configurations of insulating members may be utilized without departing from the scope of the present invention. Further, for different materials, material thicknesses, and geometries, the shape of the insulating members may be modified.

As explained above, the outer surface44of the ribs46generally contacts the inner surface21of the sidewall18of the outsert12. This may be true for any configuration of ribbing of the insert14. Accordingly, since in the preferred embodiment both the sidewall18of the outsert12and the sidewall30of the insert14are frustoconical in shape, and since the insulating members48generally extend radially inward of the insert outside diameter, the inner diameter (IDOUTSERT) associated with the inner surface21of the sidewall18of the formed outsert12at a specific horizontal plane is generally equal to the outside diameter (ODINSERT) of the ribs46. This allows the ribs46to contact the sidewall18of the outsert12and maintain a line of contact with the sidewall18to aid both the rigidity and thermal insulation properties of the insert14. This phenomena is generally true for each horizontal plane of the container10, and generally at least those horizontal planes between the circumferential straight-wall ring portion50of the insert14and the necked-down portion56of the insert14.

In another embodiment, such as that shown inFIGS. 1-4and21-22, to create a container10the insert14and the outsert12are separately formed, and the insert14is placed in the outsert12. As explained above with respect to this type of embodiment, in a preferred example this insert14is made of a foam material, and in a most preferred embodiment the insert14is made of a polystyrene foam material. In a preferred embodiment of the polystyrene foam insert14, the wall thickness of the sidewall30of the insert14is approximately 0.026″ thick, and the wall thickness of the bottom wall32of the insert14is approximately 0.042″ thick. It is understood, however, that as the material of the insert14expands the wall thickness thereof may not be completely identical throughout.

As explained above, with the embodiment ofFIGS. 1-4, the sidewall taper angles for the outsert12and insert14of this embodiment are substantially similar. Further, the inner diameter of the outsert12is substantially equal to the outer diameter of the insert14. Thus, when the insert14is placed in the outsert12, the outer surface44of the sidewall30of the insert14generally contacts the inner surface21of the sidewall18of the outsert12. In the 20 oz. example described above, wherein the sidewall taper angle (α) of the insert14is 5° 55′ 0″, and wherein the sidewall taper angle (β) of the outsert12is 5° 59′ 32″, there exist a possible clearance of 0.001″ between the outer surface44of the insert14and the inner surface21of the outsert12at a distance of 1″ from the rim26of the container10. Further, in the same 20 oz. example described above, wherein the sidewall taper angle (α) of the insert14is 5° 55′ 0″, and wherein the sidewall taper angle (β) of the outsert12is 5° 59′ 32″, there exists a possible clearance of 0.004″ between the outer surface44of the insert14and the inner surface21of the outsert12at the bottom of the second end40of the insert14. Nevertheless, accounting for manufacturing variances, there exists the possibility that the entire outer surface44of the sidewall30of the insert14, generally from the bottom wall32of the insert14to the first end38of the insert, generally contacts the adjacent inner surface21of the outsert12.

In this type of embodiment, the inner diameter (IDOUTSERT) associated with the inner surface21of the sidewall18of the outsert12at a specific horizontal plane is generally equal to the outside diameter (ODINSERT) of the insert14. This allows the outer surface of the insert14to contact the sidewall18of the outsert12and maintain an area of contact with the sidewall18to aid both the rigidity and thermal insulation properties of the container10. Even accepting the identified wall clearances above, this phenomena is generally true for each horizontal plane of the container10. As such, a pressure-fit taper lock is formed between the insert14and the outsert12when the two components are fully seated together.

As explained above and shown inFIG. 2, in a preferred embodiment the distance from the first end38of the insert14to the bottom wall32of the insert14, also identified as height (H2), is less than the distance from the first end22of the outsert12to the bottom wall20of the outsert12, also identified as height (H1). Accordingly, a gap92is provided between the bottom wall32of the insert14and the bottom wall20of the outsert. In the 20 oz. example, the gap52is 0.063″. The gap92provides several advantages. First, the gap92precludes the insert14from bottoming out on the outsert12when the two are joined, thereby allowing complete seating of the outsert12on the insert14. Second, the gap92provides an area for air to reside during the taper lock engagement of the two components. Finally, the gap92provides an additional area of insulation of the container10.

The embodiment ofFIGS. 21 and 22is substantially similar to the embodiment ofFIGS. 1-4, except the insert14has a series of insulating members in the form of flats47adjacent to ribs46. Thus, in this embodiment, like the embodiment ofFIGS. 5-9, a portion of the outer surface44of the insert14generally contacts the inner surface21of the outsert12, and a portion of the outer surface44of the insert generally does not contact the inner surface21of the outsert12. More specifically, the outer surface44of the ribs46or the area adjoining the flats47contacts the inner surface21of the sidewall18of the outsert12, but the outer surface44of the insulating members48in the form of flats47does not contact the inner surface21of the sidewall18of the outsert12. Instead, a series of air gaps82are provided between each flat47and the inner surface21of the sidewall18of the outsert12. The air gaps82generally terminate at the ribs46because the ribs generally contact the inner surface21of the sidewall18of the outsert12. Further, in the preferred embodiment where the ribs46and the flat insulating members47are vertical, the air gaps82also terminate at generally the intersection of the transition area52and the straight-wall ring portion50adjacent generally the first end38of the insert14. The air gaps82may also terminate adjacent a bottom of the flats47. However, in the preferred embodiment the air in the air gaps82is in fluid communication with the air in the gap80provided between the necked-down portion56of the insert14and the adjoining outsert12. Accordingly, in the preferred embodiment the air gaps82are in fluid communication.

A variety of methods may be utilized to fixedly connect the insert14to the outsert12, and it is understood that the methods disclosed herein are not exhaustive. As shown inFIG. 10, one assembly method that is utilized is referred to as a pressure fit method. In the pressure fit method ofFIG. 10, the insert14having the rolled rim86is inserted into the cavity19of the outsert12. In this embodiment the outsert12of this forming process has no rim. Instead, the outsert12terminates at the first end22of the sidewall18thereof. The termination at the first end22of the outsert12is fit under the rolled rim86of the insert14to lock the outsert12to the insert14.

An alternate embodiment of the pressure fit method is shown inFIG. 2. In this embodiment, when the outsert12is fully seated on the insert14of the container10, the first end22of the outsert12is substantially adjacent the rim86of the insert14. Alternatively and/or additionally, an adhesive may be utilized to join the outsert12to the insert14. One acceptable adhesive includes a formulated polyvinyl resin emulsion adhesive. This adhesive has a viscosity of 1,800 to 2,500 centipoises at room temperature. It is understood, however, that depending on the materials of the insert14and the outsert12, a variety of adhesives may be utilized under the scope of the present invention. When an adhesive is utilized, it is typically provided to an area adjacent the first end of the outsert12prior to joining the outsert12to the insert14, however, it is understood that the adhesive may be provided in alternate areas of the insert14and/or outsert12to connect the two components.

Another method, referred to as a rim lock method, is illustrated inFIG. 11. In the rim lock method ofFIG. 11, the insert14is inserted into the cavity19of the outsert12. In this method, however, the outsert12has an outwardly turned rim26. The lip35of the insert14generally fits over the rim26of the outsert12. A heated forming mandrel, or other forming means, is then used to crimp or roll the lip35of the insert14around the rim26of the outsert12to lock the lip35of the insert14to the outsert12. After the lip35is rolled it forms a rolled rim86. When the outsert12is made of a paper material the outsert12generally has an area at the rim where one layer of the rim overlaps another layer of the rim, thereby creating a possible area for leakage. This leakage or trickle, however, is substantially reduced or eliminated with the addition of the insert14having a uniform rim86overlaying the rim26of the outsert12.

FIG. 12discloses an alternate method of the rim lock method ofFIG. 11. In the embodiment ofFIG. 12, the lip35of the insert14is crimped around the rim26of the outsert12enough to provide a lock such that the formed rim86of the insert14will be connected to the outsert12. However, in this method, as opposed to the method shown inFIG. 7, the rim86is not locked entirely around the rim26of the outsert12. A similar engagement mechanism is shown in the embodiment ofFIG. 13. In this embodiment, however, the outsert12does not have a rolled rim26. Rather, a flange27extends radially away from the first end22of the outsert12. Thus, in this embodiment the flange27operates structurally and functionally as a rim for the outsert12. The lip35of the insert14is crimped around the flange27of the outsert12to provide a lock such that the rim86of the insert14will be connected to the outsert12, and the flange27will not slip out from its connection with the crimped rim86. In this embodiment the outsert12is typically made of a plastic material to provide the flange27with enough rigidity to maintain its engagement with the lip35of the insert14. It is understood, however, that this embodiment may also be made of a paper material under appropriate manufacturing conditions understood by those having ordinary skill in this art. A first alternate embodiment to that shown inFIG. 13is disclosed inFIG. 14. The embodiment ofFIG. 14operates and is manufactured in much the same way as the embodiment ofFIG. 13.

Additional alternate embodiments to that shown inFIG. 13are disclosed inFIGS. 15-16B. First, inFIG. 15, the flange27of the outsert12disclosed in this embodiment has less of an angle than the flange of the embodiment disclosed inFIG. 13. Further, the flange27of the outsert12of the embodiment disclosed inFIG. 15extends transversely from the first end22of the outsert12. When the angle of the flange27with respect to the first end22of the outsert is less than 90°, the outsert12can more easily be made of a substrate that is not a plastic, such as a paper substrate. Notwithstanding the less severe angle of the flange27in this embodiment, the lip35of the insert14is still crimped around the flange27to provide a lock between the formed rim86of the insert14and the outsert12. In the embodiment illustrated inFIG. 16A, which is typically made of a paper substrate, the flange27of the outsert12has a folded over portion29. When the outsert12is made of a paper, folding over a portion of the flange27to create the rim26assists in strengthening the rigidity of the rim26of the outsert12. Another embodiment of the vessel10is disclosed inFIG. 16B. In this embodiment the rim26, formed of the flange27and the folded over portion29of the flange, is further bent downward.

The embodiment of the vessel10disclosed inFIG. 17is similar to the embodiment disclosed inFIG. 13, however, the lip35of the insert14is not crimped around either the flange27or an outwardly turned rim26of the outsert12. Rather, the lip35of the insert14forms a resilient releasable locking mechanism which can be engaged and disengaged in a snap-fit arrangement to connect the insert14to the outsert12.

Yet another embodiment is disclosed inFIG. 18. In this embodiment, the insert14is connected to the outsert12in a snap-fit arrangement adjacent the connection of the sidewalls to the bottom walls, respectively. In the embodiment shown, the insert14has a necked-down feature56, and the outsert12also has a necked-down feature57for stacking purposes. Accordingly, the neck-down feature56of the insert14engages the necked-down feature57of the outsert12to lock the insert14to the outsert12.

In a preferred embodiment, while the formed rim86of the insert14is connected to either the rim26of the outsert12, in the case of the embodiments shown inFIGS. 11-17, or to the first end22of the sidewall18of the outsert12, in the case of the embodiment shown inFIGS. 2 and 10, the remaining portion of the insert14is generally not fixedly attached to the outsert12. As such, the remaining portion of the insert14, such as the ribs46and insulating members48in one embodiment, are free to float within the cavity19of the outsert12. Similarly, the bottom wall32of the insert14merely rests on the bottom wall20of the outsert12, or is spaced a distance from the bottom wall20of the outsert12. In alternate embodiments, however, a portion of the sidewall30of the insert and/or the bottom wall32of the insert14is fixedly connected to the inner surface of the outsert12.

It has been found that the container10manufactured in accordance with the one of the examples described above (i.e., that shown inFIGS. 1-4and having a paper outsert12and a polystyrene foam insert14), provides a substantial improvement for reducing the thermal transfer of heat to the outsert12of the container10. As shown in the TABLE 1 below, this embodiment provides a reduction in the sidewall temperature of the container10over all other tested cups, as well as providing the least amount of temperature change in surface temperature, meaning that the temperature of the liquid in the cup was maintaining a fairly constant temperature. Thus, the container10provides an improvement over the prior art cups. Specifically, a test was performed on a variety of 20 oz. cups. First, boiling water having a temperature of about 190° F. was placed in each cup and the cup was capped. A thermocouple was positioned on the outside sidewall of the cup at ½ of the cup height. Sidewall temperatures were taken by the thermocouple at 7 intervals (30 seconds, 1 minute, 2 minute, 3 minute, 4 minute, 5 minute and 10 minutes). The data is provided in TABLE 1 below.

In another example of an embodiment of the container10described above (i.e., that shown inFIGS. 5-9and having a paper outsert12and thermoformed polypropylene insert14having a plurality of arcuate insulating members48) also provides a substantial improvement for reducing the thermal transfer of heat to the outsert12of the container10. As shown in the TABLE 2 below, this container10provides a 22% reduction in the sidewall temperature of the container10over a non-insulated cup. Thus, in this embodiment the container10also provides an improvement over the prior art cups. Specifically, a test was performed on a variety of 16 oz. cups. First, boiling water having a temperature of about 212° F. (100° C.) was placed in each cup and the cup was capped. A thermometer was inserted through a hole in the cap and extended into the water to a distance of ½ of the cup height. Additionally, a thermocouple was positioned on the outside sidewall of the cup at ½ of the cup height. Sidewall temperatures were taken by the thermocouple after the water had cooled to about 190° F. (87.8° C.). Five samples were tested for each cup type and the average is provided in TABLE 2 below.

Accordingly, the vessel10of the present invention provides a simple and inexpensive means for improving the thermal insulative properties of beverage containers. Specifically, the present invention provides a vessel10which minimizes heat transfer to the outsert12, has a low cost, is easy to manufacture and provides superior performance. As such, the present invention overcomes the deficiencies seen in the prior art.

Several alternative embodiments and examples have been described and illustrated herein. A person of ordinary skill in the art would appreciate the features of the individual embodiments, and the possible combinations and variations of the components. A person of ordinary skill in the art would further appreciate that any of the embodiments could be provided in any combination with the other embodiments disclosed herein. Additionally, the terms “first,” “second,” “third,” and “fourth” as used herein are intended for illustrative purposes only and do not limit the embodiments in any way. Further, the term “plurality” as used herein indicates any number greater than one, either disjunctively or conjunctively, as necessary, up to an infinite number.

It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. Accordingly, while the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention and the scope of protection is only limited by the scope of the accompanying Claims.