Thermally Insulated Food Bag

This invention relates generally to containers, and particularly to a soft-sided thermally insulated carrying bag.

There is a need in certain fields for soft-sided thermally insulated carrying cases. One particular application is in the ready-to-eat pizza field, where hot pies are packaged in rectangular cardboard cartons and delivered several cartons at a time to customers' homes or offices. It is desirable that these pies be carried in a convenient container which has a capacity of several cartons, and which is light so as not to add unduly to the delivery person's burden. In addition, the container should also be flexible so that it can be easily folded up when desired. But at the same time, such a container should have good thermal insulating qualities in order to keep the contents as warm as possible during delivery, and the material of which the container is made should be of such a nature that is does not become easily soiled if some of the contents should leak out of the cartons.

In order to accomplish these objectives, as well as others which are important in the delivery of ready-to-eat food items, the present invention provides a thermally insulated food carrier comprising panel means including thermally insulating flexible sheet material arranged to form a bag having at least a top panel and a bottom panel, and defining a side opening to facilitate insertion of containers of warm material into the bag. Closure means are provided, including thermally insulating flexible sheet means, a proximal portion of which is hinged to the panel means whereby the closure means moves from a first position, in which the closure means exposes the side opening in order to facilitate loading of the bag, to a second position in which the closure means covers the side opening in order to retain heat within the bag. Fastening means are adapted to secure a distal portion of the closure means to the panel means whereby to retain the closure means in the second position.

These features and advantages, as well as others which inhere in the various embodiments of the invention, will be more fully appreciated after a reading of the following detailed description, when taken in conjunction with the accompanying drawings, also described below.

FIG. 1 is a perspective view of a first embodiment of a thermally insulated carrying bag in accordance with the present invention, with parts broken away to reveal details of internal construction;

FIG. 2 is a fragmentary sectional view of the fabric sandwich employed in the bag of FIG. 1, taken along the lines 2--2;

FIG. 3 is a fragmentary side elevational view of the bag of FIG. 1 when in its closed and secured condition, with parts sectioned for clarity of illustration;

FIG. 4 is another fragmentary side elevational view of the bag of FIG. 1 when in its closed and secured condition;

FIG. 5 is a perspective view of an alternative embodiment of a bag in accordance with this invention;

FIG. 6 is a fragmentary perspective view of the assembled bag of FIG. 5;

FIG. 7 is a perspective view of the bag of FIG. 6 showing another embodiment of the bag straps and handle;

FIG. 8 is a partial perspective view of the bag of FIG. 7 with the lining pulled out of the bag.

Referring first to FIGS. 1 through 4, a thermally insulated container in accordance with the present invention, generally designated 10, is provided for the purpose of carrying a number of rectangular cardboard cartons 12 of the type in which hot pizza is customarily packaged for delivery to customer locations. The bag is formed of a top panel 14, a bottom panel 16, a side panel, one edge of which is visible at 18, and a pair of opposite side panels 20. These panels are sewn or otherwise fastened to each other along seams 21. The top, bottom and side panels define a side opening 22 through which the pizza cartons 12 are loaded into the interior of the bag 10.

A pair of straps 24 are arranged in an X-configuration across the top panel 14, and their ends are sewn into the seams 21 between top panel 14 and side panels 20 in order to secure the straps to the bag for the purpose of providing a carrying handle. The straps also permit the bag to be worn by the delivery person as a backpack.

A rigid metal frame 26 is preferably inserted into the bag for the purpose of expanding it to its full volume in order to facilitate the insertion of the pizza cartons 12.

In order to minimize heat loss, and to keep the bag 10 as clean as possible, each of the panels mentioned above is formed of a thermally insulating and water-repellent material. Furthermore, in order to make the bag as light as possible and to permit it to be folded up when desired, these panels are formed of flexible sheets.

The preferred material for this application is a three-layer sandwich of the kind illustrated in FIG. 2. On the outer surface of each panel is a water-repellant layer 30. On the inner surface of each panel is a waterproof layer 32. And between these two water-resistant layers is a thermally insulating layer 34. The latter layer is preferably made of a material such as that which is sold by Minnesota Mining & Manufacturing Co. (3M) under the trademark Thinsulate, which comprises a thin, porous sheet 36 of loosely packed plastic (preferably olefin and polyester) fibers bonded to a backing sheet 38. The inner lining 32 is preferably a material such as DuPont pack cloth. The outer layer 30 is preferably a material such as that which is sold by DuPont under the trademark Cordura. When so constructed, the entire bag 10 is machine-washable.

At the bottom edge of the side opening 22 the bottom panel 16 has an integral extension 16A which serves as a main closure flap, while at the top edge of the side opening 22 the top panel 14 has a somewhat shorter integral extension 14A which serves as a top auxiliary closure flap. The purpose of the closure flaps is to fold over the side opening 22 in order to secure the contents within the bag and to further minimize heat loss therefrom.

To assist in providing a heat-retaining closure, the side panels 20 are provided with respective gusset-forming sewn-in tucks or seams 50 extending down the middle of the side panels a short distance from the side opening 22. The gussets thus formed allow those portions of the side panels 20 which are beyond the edge of the pizza cartons 12 to collapse inwardly of the bag 10. In order to force them to collapse inwardly in such manner, pairs of tie straps 52 and 54 are provided on opposite sides of each gusset, and are secured in place by having their proximal ends sewn in to the adjacent seam 21.

In addition, the straps 54 are provided with buckles 56 which buckle up to the free, or distal, ends of their associated straps 52 so that the upper ends of each side panel can be pulled into a collapsed configuration. This closes off the sides of the side opening 22 of the bag 10, thus impeding communication at those locations with the cooler air outside the bag. The side straps further draw together the top and bottom panels to curl the bottom panel upward into a dish-like configuration in order to contain the contents of the bag in the event of spills. After the upper portions of the side panels 20 have been collapsed in this manner, the flap 14A is folded over the pizza cartons 12 as seen in FIGS. 3 and 4, and the flap 16A may then be folded over the flap 14A in order to complete the closure of the side opening 22.

In order to secure the flaps 14A and 16A in position to close the side opening 22, fasteners, preferably strips of cooperating textile hook and eye fasteners of the type sold under the Velcro trademark, are provided to secure the flap 16A in place over the flap 14A. A first Velcro strip 60 is sewn or otherwise attached to the upwardly facing surface of flap 14A, and a second Velcro strip 62 of a cooperating type is sewn or otherwise fastened to the downwardly facing surface of flap 16A. When the flap 14A is folded over, and the flap 16A is folded over flap 14A, the Velcro strips 60 and 62 engage to form a secure heat-retaining closure.

The alternative embodiment of FIG. 5 is a bag 110 very similar to that of FIGS. 1-4, but having a somewhat different closure system. In order to call the reader's attention to the similarities between these two structures, all elements in FIG. 5 which correspond to elements of FIGS. 1-4 are given reference numerals exactly 100 units higher than those given to the corresponding elements in FIGS. 1-4.

In the embodiment of FIG. 5 the side panels 120 do not have any gussets, but instead they are provided with integral extensions in the form of respective outwardly extending side auxiliary flaps 170. In addition, the top flap 114A is not attached to either of the side flaps 170. This permits the flap 114A to be folded flat over the pizza cartons 112 and each of the flaps 170 then to be folded flat over the flap 114A.

Furthermore, an additional Velcro strip 161 is secured to the outwardly facing surface of flap 114A in position to be enclosed by the flaps 170. To engage Velcro strip 161, both flaps 170 are provided with cooperating Velcro strips 172 on their respective inwardly facing surfaces and along their respective upper edges. Accordingly, regardless of which flap 170 is folded over first, the entire length of the Velcro strip 172 of that flap 170 will fasten securely to a portion of the length of the Velcro strip 161, and a portion of the length of the Velcro strip 172 of the other flap 170 will fasten securely to the remaining length of the Velcro strip 161.

In addition, the flaps 170 are long enough so that their respective outer edges 170A overlap when the flaps 170 are folded over each other, and these outer edges 170A are provided with respective Velcro fasteners 174 on the respective outwardly facing surfaces of their edges 170A, as well as respective Velcro fasteners 176 on the respective inwardly facing surfaces of those edges. Moreover, the Velcro fasteners 174 are of the type which cooperate with the Velcro fasteners 176. As a result, no matter which one of the flaps 170 is folded over the flap 114A first, the outwardly facing Velcro fastener 174 of that flap 170 will engage securely with the inwardly facing Velcro fastener 176 of the other flap 170 when the latter is folded thereover.

After both of the flaps 170 have been folded over, the flap 116A is then folded over both of the flaps 170 in turn, and the Velcro fastener 162 thereof securely engages with the Velcro fastener 160 on the top panel 114. This fully seals off the side opening 122 of bag 110 in both a thermal and a mechanical sense.

Thus a superior-heat-retaining closure is formed by first folding the flap 114A flat over the pizza cartons 112, then folding both of the flaps 170 flat thereover in any order, causing the Velcro fasteners 172 of boths flaps 170 to adhere to the Velcro fastener 161, and the Velcro fastener 174 of one of the flaps 170 to adhere to the Velcro fastener 176 of the other flap 170. Finally, the flap 116A is folded flat oer the flaps 170, causing the Velcro fastener 162 to adhere to the Velcro fastener 160.

Because of the previously noted fact that the ends of the straps 24 are attached where the top panel 14 or 114 meets the side panels 20 or 120, the straps do not interfere with the opening and closing of the flaps 14A or 16A, or the flaps 114A, 116A, and 170; nor do they interfere with the operation of any of the Velcro fasteners described above. As shown in FIG. 6, the bag 110 can be suspended by the straps 24 which do not cross the side opening 122 or otherwise hamper access to various objects carried inside the bag. These objects, such as bowls, cups, trays and other containers for ice cream, salad, soup and other hot or cold substances, are retained and stabilized in their original positions during transportion. The parallelepiped shape of the bag permits the stacking of bags, accommodation of objects with different shapes and sized, and stabilized positioning of the bag and its contents on any horizontal support.

A handle 178 located at the point of intersection of the straps 24 can be integral with the straps, as shown in FIG. 6, or a handle 178 detachably connected thereto by virtue of buttons 180, as illustrated in FIG. 7, or other suitable means. The straps 24 shown in FIG. 7 are sewn into or otherwise permanently secured to the bag. These straps encircle the bag, except the top panel 114, thereby reinforcing the bag structure. The straps 24 are attached to the outer confines of the bag, depicted in FIGS. 5 and 6, at a juncture 182 and 184 of the top and side panels near the side opening 122, and at 186 and 188 on the opposite side of the top panel 114.

All flaps are releasably interconnected at one peripheral portion of the bag which is defined by the Velcro strips 160 and 161. Each of the side flaps 170 has an inside L-shaped fastener extending along the outer edges 170A and comprising the Velcro strips 172 and 176. The flaps 170 have the outside strip fastener 174. The side flaps 170 couple each other by the cooperating fasteners 174 and 176 and seal off the portions of the opening 122 by further attachment of the side flaps to the top flap 114A by virtue of the co-acting fasteners 172 and 161. The bottom flap 116A overlaps the coupled side flaps 170 and further partially seals the opening 122 when the fasteners 160 and 162 are interlocked.

The inner lining 190 is stitched to the bag only along the perimeter of each flap. The lining 190 can therefore be pulled out of the bag, by grasping a bottom portion 192 of the lining, and turned inside out as shown in FIG. 8. This feature permits better cleaning of the soiled bag surfaces by exposing the lining to washing and drying processes and by preventing the coupling of the Velcro fasteners during these processes. Alternatively, the inner lining 190 can be completely removed from the bag if it is connected to the bag by Velcro fasteners or other releasable fastening means.

It will now be appreciated that this invention provides a more practical and effective heat-retaining enclosure and carrying container for a number of carton-enclosed pizzas as they are being delivered to a customer's office or residence.

The foregoing detailed description specifies embodiments which are presently preferred, and which serve to illustrate this invention. But other embodiments may be imagined now or in the future which might incorporate one or more aspects of the invention. Therefore the scope of protection accorded should not be limited to the particulars of this description, but instead should be determined by the following claims. These claims, moreover, should be interpreted consistently with the general principles and novel teachings expressed herein.