Abstract:
A single-piece seamless construction container formed from a thermoformable material, the container including a vessel, at least one wing, and at least one hinge coupling the wing to the vessel. The wings comprise a patterned surface, although only the vessel, or the wings and the vessel may also be configured to include a patterned surface. The wings are configured to wrap about the container with the patterned surface serving to trap air between an outer surface of the vessel and an inner surface of the wing. The trapped air and the wing forms an insulative air gap between a surface of the container and the wing. The container may be nestably stacked in a wing open or wing closed position.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     This invention relates to the art of single piece containers, and more particularly to thermally insulated single piece seamless construction containers.  
         [0003]     2. Brief Description of the Prior Art  
         [0004]     When a consumer or user carries a disposable paper cup or a single walled plastic container containing coffee, tea, or other food products commonly sold and dispensed, in many instances the temperature of the contents of the container is such as to create discomfort in the hands and fingers of the holder. That is, paperboard and certain plastic cups typically do not inherently provide sufficient thermal insulation or moisture barrier properties when filled with hot or cold beverages or other food products. The transfer of temperature from the liquid or contents through the container to the holder&#39;s hand can cause handling and consumption problems.  
         [0005]     To combat these problems, convenience stores and fast food retail outlets often “double cup” (use a pair of nested cups) for coffee and other hot drinks. The outer drink cup and the air gap between the two cups provides a level of thermal insulation for the hot beverage contained within the inner drink cup. Another approach employed by some manufacturers of both paper and plastic containers is to provide an integral band of synthetic material that is formed in the manufacturing process to provide an insulative layer. Both of these approaches tend to be expensive.  
         [0006]     More recently, a number of persons have designed and provided disposable “sleeves” that slip over the outside surface of a drink cup to provide insulation between the contents of the cup and the hands and fingers of the holder. These sleeves take numerous forms and are commonly made of paper or other insulative materials. One characteristic common to most or all of these sleeves is the fact that they are opaque and, for this reason, obscure the trade dress and ornamental designs which the manufacturers of the hot drink cups take pains to provide.  
         [0007]     Another general problem with certain drink cups is that they are constructed with two pieces of plastic that have to be formed and bonded together. More specifically, such two-piece cups are generally formed from a sidewall sheet of thermoformable plastic material whose ends are overlapped somewhat and bonded to one another to form a longitudinal sidewall seam. A bottom disc is then bonded to an annular bottom flange integral with the side wall to form a seal therebetween.  
         [0008]     This conventional two-piece cup construction presents the problem of weakening of the lower bottom edge of the cup due to stresses that are induced by the heat and pressures involved in bonding the bottom wall disc to the side wall flange. Weakening of the annular bottom edge of the cup may, in turn, cause it to rupture thereby spilling the cup contents. The possibility of rupturing the bottom edge of the cup is especially acute if the cup is dropped some distance when filled with liquid or other food products.  
         [0009]     Because of the foregoing deficiencies in the art, it would especially be desirable if a single piece seamless construction container could be provided which includes an insulative layer coupled to the container in order to protect the holder&#39;s hand and fingers from the temperature of the contents therein, and also to minimize (if not eliminate entirely) the stresses at the bottom edge of the cup which are induced by the heat and pressures during the fabrication process. It is toward providing such a container that the present invention is directed.  
       SUMMARY OF THE INVENTION  
       [0010]     The present invention relates to a single piece seamless construction container and method of making therein, advantageously configured to provide a sturdy construction and an insulative layer for protecting the holder&#39;s hand and fingers from discomfort due to hot or cold temperature transfer through the sidewall of the container. In general, this is achieved by providing a single piece seamless construction container, and preferably two wings coupled with the container, although one or a plurality of wings may be used. The wings are configured to wrap about the container, preferably spaced apart from a surface of the container, and are adapted to form an insulative air gap between the surface of the container and the wing.  
         [0011]     The wings preferably comprise a patterned surface such as flutes, dimples, or ridges that are thermoformed into the material in sheet form during the manufacturing process. Other patterns are possible which may include design logos or other indicia. Furthermore, the container and/or the wings may be transparent, allowing for a user to visualize design logos or other indicia located on a surface of the container or a wing, and also to see the contents of the container.  
         [0012]     Alternatively, the patterned surface may be thermoformed into the container, allowing the wing to remain smooth. This creates a smooth insulative outer surface for printing of logos and other indicia.  
         [0013]     As an additional alternative, both the container and the wings may include a patterned surface.  
         [0014]     The container according to the present invention is further uniquely adapted to efficiently nestably stack in either a wing open or wing closed position in order to promote efficient bulk transportation of the containers to wholesale, retail, or other end users. The containers can readily nest without becoming wedged or telescoped together.  
         [0015]     It is a further object of the invention to improve the gripability of a cup or container.  
         [0016]     Yet another object of the invention is to thermally insulate the hand and fingers of a user from the liquid or food product held in a container.  
         [0017]     Yet another object of the invention is to provide a container that has improved strength characteristics over two or more piece construction containers. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a perspective view of a unitary double walled container according to the present invention.  
         [0019]      FIG. 2  is a side elevation view of the unitary double walled container of  FIG. 1  in a wing open position.  
         [0020]      FIG. 3  is a side elevation view of the unitary double walled container of  FIG. 2 , showing the wings partially folded down.  
         [0021]      FIG. 4  is a side elevation view with a partial section of the container of  FIG. 1 , showing the insulative wing and air gap.  
         [0022]      FIG. 5  is a cross section view taken along line  5 - 5  of the container of  FIG. 4 , showing the bottom support configuration and insulative wings in a folded down position.  
         [0023]      FIG. 6  is a fragmentary cross section view taken along line  6 - 6  of the container of  FIG. 9 , showing the hinge detail in a wing open position.  
         [0024]      FIG. 7  is a fragmentary view of the hinge detail of  FIG. 6 , showing the hinge detail in a wing folded down position.  
         [0025]      FIG. 8  is a top plan view of a single sheet of thermoformable material, after the vessel has been thermoformed, and after the wings have been cut, but before the wings have been thermoformed.  
         [0026]      FIG. 9  is a top plan view of the container of  FIG. 8 , after the wings have been thermoformed. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0027]     Although the disclosure hereof is detailed and exact to enable those skilled in the art to practice the invention, the physical embodiments herein disclosed merely exemplify the invention that may be embodied in other specific structure. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.  
         [0028]     For instance, it is noted that the unitary double walled container disclosure of the present invention is particularly suited for holding beverages, such as coffee. However, the container of the present invention could easily be modified in form to contain any other foodstuffs. For instance, it is within the scope of the present invention to modify the generally cylindrical structure of the disclosed container to a box or other shaped container, to resemble a pizza box or other hot or cold lunch container.  
         [0029]     The seamless construction container as hereinafter described in detail is made of plastic, preferably of PET (polyethylene), [** is PET correct???**] although other suitable materials may be used. Such containers have marked advantages over paper cups that have been impregnated or coated with wax. They present a better feel and taste to the lips, they do not become soggy in use, and they form a substantially perfect vapor barrier so that no moisture condenses on a cool table beneath a cup when the cup contains hot coffee or the like.  
         [0030]     Referring now to the drawings, wherein like numerals represent like parts throughout the views, there is generally designated at  10  an ergonomically designed, unitary double walled container according to the present invention. As seen particularly in  FIGS. 1 and 2 , the container  10  includes a vessel portion  12  preferably coupled by way of a hinge or hinges  65  to preferably two winged portions  14 , although any number of wings may be used.  
         [0031]     The generally cylindrically shaped vessel  12  incorporates a closed bottom  30  and an open top  35 . The vessel  12  preferably has a rim or lip  25  at the open top  35  which may be curled over. The rim  25  at the open top  35  may be adapted to fit any existing lid or cover (not shown), according to the size of the container  10  and the preference of the purchaser/end-user.  
         [0032]     In a preferred embodiment, the vessel  12  includes an upper sidewall portion  15  and a lower sidewall portion  20 . The lower sidewall  20  preferably includes a plurality of ribbing  17  in order to provide structural support and strength to the container  10 , although other suitable structural support such as ridges or fins may be used. The lower sidewall portion  20  is also preferably adapted for placement in a cup holder, such as a vehicular cup holder.  
         [0033]     As best seen in  FIGS. 4 and 5 , the bottom  30  of the vessel  12  may be formed with a punt or raised main central portion  32  integral with an annular supporting marginal portion  31 . The raised main central portion  32  improves the strength of the closed bottom  30 .  
         [0034]     Attention is now directed to the winged portion  14  as best seen in  FIGS. 3, 4 , and  9 . The winged portion  14  comprises an integral thermoformed segment of the container  10 , coupled to the vessel  12  by way of a hinge  65  or other conventional coupling means. Preferably, the wing  14  is formed in a manner as to be in surrounding contact with the circumferential upper sidewall portion  15  when wrapped about the vessel  12 , as indicated by the directional arrows  90  in  FIG. 3 . The wing  14  may then be secured about the vessel  12  by fastening means such as a tab  155  and a receiver  160 . Alternatively, the wing  14  may also be formed to be in surrounding contact with both the upper sidewall portion  15  and the lower sidewall portion  20 .  
         [0035]     Although a particular type of end fastening means is disclosed, it will be understood and appreciated by those skilled in the sheet materials art that any of several different end fastening mechanisms, such as tabs and slots, adhesives, or snap buttons may be used. Examples of alternative fastening means can be seen at  55  and  60 , and  255  and  260 , in  FIGS. 2 and 8  respectively. Alternatively, the bands may be preformed into sleeves and permanently joined. It is also possible to thermoform seamless sleeves, usually by forming a cup and later removing the bottom.  
         [0036]     As can be best seen from  FIGS. 1 and 4 , in a preferred embodiment, a surface pattern  52  is applied to the wings  14 , although a surface pattern  52  applied to only the vessel  12 , or both the vessel  12  and the wings  14 , is within the scope of the invention. The surface pattern  52  serves several purposes. The surface pattern  52  may contact the vessel  12 , forming a structural member of the wing  14 . Referring to  FIG. 4 , the surface pattern  52  can also preferably serve to trap air  80  between the outer surface  40  of the vessel  12  and the inner surface  51  of the wing  14 , thereby forming an insulating layer. The surface pattern  52  also may assist nestability of the containers  10  in stacked form for shipping. The surface pattern  52  adds rigidity to the wing  14 , which in turn provides for additional structural support for the container  10 . The surface pattern  52  also serves as a convenient finger grip and contact surface.  
         [0037]     The surface pattern  52  may be any pattern, such as a fluted pattern, hemispheres (either raised or depressed), cylindrical rings, geometric figures, slogans or trademarks, or cartoon characters in any combination, depending on manufacturer/purchaser preference.  
         [0038]     Referring now to  FIGS. 6 and 7 , the rim  25  of the vessel  12  and the hinge  65  are shown. In a preferred embodiment, a predetermined distance X is greater that a predetermined distance Y. Preferably, distance X is equal to the diameter of the rim. The relationship between distance X and distance Y is important in order to allow the hinge  65 , preferably comprising a rim arm  70  and wing arm  72 , to be positioned within the space  27  defined by the rim  25 . The hinge  65  preferably comes to a point to effectuate the rotation of the hinge  65  into the space  27  under the rim  25 . Preferably all but a slight amount of the hinge  65  is formed in the secondary thermoforming operation.  
         [heading-0039]     Method of Manufacture  
         [0040]     The preferred method of manufacturing the container  10  is multi-progressive thermoforming. Multi-progressive thermoforming is comprised of a series of thermoforming steps in order to produce the container  10 . However, any material may be used, such as but not limited to, polystyrene, paper, or other materials. Additionally, a polystyrene sleeve could be applied to the outer wall of the inner cup prior to final assembly.  
         [0041]     The first step is to pre-form the vessel  12 . A flat sheet of pre-heated thermoformable material, such as PET (polyethylene), polystyrene, polycarbonate, nylon, acetate, polyvinyl chloride, saran, etc., is placed over a cavity opening. By choosing the desired sheet material and further selecting the appropriate properties for the selected material, the container can be formed of a material that is tailored to the product end use, i.e. to retaining the contents to be put into the container and to being disposable or recyclable. Next, a vacuum is applied to the tool cavity, sucking the vessel portion  12  of the container  10  down within the cavity in order to define the vessel  12  shape. The lower sidewall support ribbing  17  may also be formed during this first thermoform. The punt  32  integral with the closed bottom  30  is also preferably formed during the first thermoform.  
         [0042]     At this point in the manufacturing process, the wings  14  will need to be trimmed out of the flat part of the thermoformable material. A stamping die next stamps out the outline of a wing or wings  14 , and the means for coupling the wings  14  together about the vessel  12 . At this time, the wings  14  will still be flat, as can be seen in  FIG. 8 .  
         [0043]     The second thermoforming stage is next. Referring now to  FIG. 9 , this secondary thermoforming stage provides contour to the wings  14 , such that the wings  14  advantageously fit about the vessel  12 . Preferably, the secondary thermoforming stage also forms the surface patterns  52 . Also, preferably, the rim  25  and hinge  65  contours are formed during the secondary thermoforming step.  
         [0044]     Also within the second thermoforming stage, contour is preferably provided for the wing  14  coupling mechanism, such as tabs  255  and slots  260 .  
         [0045]     At this stage the container  10  may now be stacked for shipment to wholesalers, retailers, and end users. When the container is ready to be utilized for an intended purpose, the wing or wings  14  are wrapped downward and inward about the vessel  12 , as shown by arrows  90  in  FIG. 3 , wherein the fastening means preferably restrain the wings  14  in a wing  14  closed position. It is also within the scope of the present invention wherein this stage of wrapping the wings  14  about the vessel  12  is completed before the containers  10  are stacked for shipment.  
         [0046]     The foregoing is considered as illustrative only of the principles of the invention. Furthermore, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described. While the preferred embodiment has been described, the details may be changed without departing from the invention, which is defined by the claims.