Dynamically expandable container
A container having an expandable thickness for better insulation. The container has two walls which may be expanded to form an insulating air space therebetween. The expansion may be caused by compressible foam, an expandable strip material, a projection running on an inclined surface arrangement or by a gas generating material. The expansion may be activated by removing a vacuum, pulling a physical strip, by rotating one layer within the other or by crushing microcapsules to release gas. The expanded container provides better insulation for hot foods but allows a smaller thickness for storage.
1. Field of the Invention
The present invention relates generally to a container for hot food products and more particularly to a container having an expandable space between two layers to provide a thermally insulating space to prevent hot food from cooling.
2. Description of the Background
Due to the pace of modern life, it has become very common for many people to rely on carry-out food services for the preparation of many of their meals. This presents a special problem for the food providers since food which is prepared and sold at a certain temperature may be very delectable, but is less tasty if the food is allowed to cool before eating. While this may be a problem of a lesser degree if the food is being eaten on the spot, it is a real difficulty for take-out services. Over the years, a number of different types of containers have been developed, especially of the paper product variety and especially with various coatings to prevent the moisture from the food from softening the paper. Other products have also been used, such as styrofoam which provides insulation in the thickness of the container wall.
No matter what the actual material, the user of a container is faced with a two pronged problem. On the one hand, a thicker walled container typically provides better insulation and allows the customer to keep his food hot longer, thus providing a better experience for the customer. On the other hand, thicker walled material require additional storage space and often additional cost. Thus, it is difficult to have a container which is thin for storage and transportation but which provides superior insulation ability in use.
SUMMARY OF THE INVENTIONAccordingly, the present invention is an improvement over previous arrangements by providing a container which is thin for storage, but which can be dynamically expanded at the time of the use.
The present invention further provides a two walled container which has walls close to each other for storage and which are expanded in use to provide extra insulation.
The present invention also provides a two walled container which is expanded before using.
The present invention still further provides a multi-walled container which is expanded during use to provide for extra space between the walls.
The present invention provides a double walled container having compressed foam inserts under pressure between the walls which are expanded upon use to provide an air space between the walls.
The present invention also provides a double walled container having a flat insert between the layers, which when activated forms an expanded shape to separate the walls and provide extra insulation.
The present invention further provides a double walled container having corresponding shapes which when rotated causes the shapes to separate and provide space between the walls.
The present invention further provides a container having double walls with a material placed therebetween to generate gas when activated.
The present invention also provides a method for expanding a container.
Briefly, the invention achieves this by providing a container in the form of a bowl or bag which has two layers with a mechanism therebetween which can be released by a physical action such as pulling a string, by releasing a vacuum seal or by crushing microcapsules or a matrix material or allowing reactants in separated chambers to come together, to generate gas so as to force the two layers apart and leave an air space between the layers which acts as insulation.
BRIEF DESCRIPTION OF THE DRAWINGSThe present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
Referring now to
The foam is compressed in the storage state and allowed to expand in the expanded state as shown in
The particular manner of compression is not as important as the fact that the two layers may be expanded to allow an air space to be formed between layers 12 and 14. This dead air space acts as a marvelous insulator and retains generally more heat than traditional single walled containers. The lips 18 and 19 are originally formed as shown in
Although the present invention has been described in terms of a bowl shape, similar arrangements can be made in the form of a plate, or even in the form of a bag for carrying the food home. Lids having this arrangement could also be supplied. Also, although the discussion centers on keeping foods hot, it is equally applicable for cold foods which must remain cold. Of course, the containers can be used for materials other than food which require heat retention.
The second embodiment of the invention is shown in
In
In order to actuate the expandable material, a strap 28 is attached to one end thereof. The employees prepares the container for use by pulling on the strap, which causes the expandable material to stretch and form the extended arrangement causing the two walls to separate. The actual shape of strap 28 is unimportant and can be a loop, a handle or a tape and may be of any material which is strong enough to withstand the pulling necessary to expand the material.
The strap can serve a second purpose of bundling the two walls of the container, or in configurations of a container and matching lid, the strap can serve to tie the lid and container together in storage. The strap can loop around the container and lid elastically or can be a two strap arrangement tied together by any convenient fastening means including clips, velcro, buttons, spring biased fasteners and the like.
A third embodiment is shown in
The recesses 38 are placed equally around the bottom of the outer layer 32. The extent of each recess must be short enough that the recesses do not contact each other. However, the recesses must be otherwise long enough so that the incline in the recess is gentle enough for the projection to move easily. Although the example shows 3 projections on 3 recesses, any number can be utilized as long as the number of projections and recesses are similar.
A fourth embodiment is shown in
In each of these cases, the distance between the two layers of the container is increased. For example, in the embodiment of
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Claims
1. An expandable container comprising:
- a inner wall;
- an outer wall, said inner wall being nested in said outer wall; and
- an expander between the walls so that the walls, the expander increasing distance between the inner wall and outer wall to provide greater heat insulation.
2. The container according to claim 1, wherein the container is a bowl.
3. The container according to claim 1, wherein the container is a plate.
4. The container according to claim 1, wherein the container is a bag.
5. The container according to claim 1, wherein the container includes an expandable lid.
6. The container according to claim 1, wherein the means for expanding includes at least one foam material compressed under pressure, which expands on the release of the pressure to force the inner wall and the outer wall apart.
7. The container according to claim 6, wherein the foam material is compressed using a vacuum seal and is allowed to expand by breaking the seal.
8. The container according to claim 6, wherein the foam is held in a compressed state by a strap and is released by removing the strap.
9. The container according to claim 1, wherein the expander is a sheet of material having slits which forms an expanded material by being pulled.
10. The container according to claim 1, wherein the expander includes projections on one wall and sloping recesses on the other wall which meet, with the projections sliding on the sloped walls of the recess to push the walls apart.
11. The container according to claim 1, wherein the expander includes a layer of material which generates gas when activated.
12. The container according to claim 11, wherein the material includes microcapsules of citric acid and bicarbonate.
13. The container according to claim 1, wherein the expander is a set of screw threads on each wall.
14. The container according to claim 1, wherein the expander is an accordion mechanism between the two walls.
15. The container according to claim 14, where the outer wall is a film which is stretched when corrugations of said accordion are unfolded.
16. A method of expanding a container to increase its thermal insulation, comprising:
- providing an inner wall and an outer wall which are nested;
- providing an expandable device between the inner wall and the outer wall; and
- activating said expandable device to create a larger space between said inner wall and said outer wall.
17. The method according to claim 16, wherein the expandable device is a foam material.
18. The method according to claim 16, wherein the expandable device is a slitted material.
19. The method according to claim 16, wherein the expandable device is an arrangement of projections from one wall and recesses having a sloped bottom on another wall.
20. The method according to claim 16, wherein the expandable device is a material which is capable of generating gas.
Type: Application
Filed: Nov 19, 2004
Publication Date: May 25, 2006
Inventors: Vladimir Vasil' Yev (Saint-Petersburg), Dmitry Logatchev (Saint-Petersburg), Alexander Medvedev (Saint-Petersburg), Nikolav Shkolnik (West Hartford, CT), Andrei Matioushenko (Saint-Petersburg)
Application Number: 10/992,290
International Classification: B65D 81/38 (20060101);