This application claims priority to U.S. Provisional Patent Application Ser. No. 60/646,093, filed Jan. 21, 2005, and U.S. patent application Ser. No. 11/334,808, filed Jan. 18, 2006, both entitled “MICROWAVABLE CONTAINER WITH SLEEVE,” which are incorporated herein by reference.
The invention relates generally to the packaging of edible products. More particularly, the invention relates to a packaging assembly adapted for microwave oven cooking that reduces material requirements, optimizes space, and facilitates handling of the microwavable container by the consumer when the contents of the container are hot.
Consumers often prefer to cook food in a microwave oven rather than conventional ovens because of the reduced cooking time required to heat foods in a microwave oven. As a result, a wide variety of food items have been designed for heating in a microwave oven. Popular examples of these items include lasagna, cheese macaroni dishes and vegetable casseroles.
Microwave ovens do not transfer heat to a material in the same manner as conventional ovens. Rather, the material is induced to heat itself as the microwave oven generates a continually changing electrical field. Accordingly, microwave cooking requires containers that are transparent to microwave energy.
A variety of trays and containers have been developed specifically for microwave heating. For example, Matsui U.S. Pat. No. 4,704,510 discloses a container for food service which is adapted to withstand heating in a microwave oven. The container is formed from a laminate sheet material consisting of a non-stretched polyethylene terephthalate film laminated to the interior of a foamed plastic sheet. The bottom of the container is raised to curve concavely towards the center thereof to distribute the container contents and improve upon the heat distribution within the container during the heating or cooking of the contents with microwave radiation. However, the laminated container material utilized is relatively expensive to construct.
Bowen, et al. U.S. Pat. No. 4,486,640 relates to a utensil for cooking and/or baking foods in a microwave oven in which a generally flat-bottomed container base incorporates a removable tray and a closure lid possessing apertures to enable the escape of steam which is generated during cooking. This microwaveable container structure is relatively complex and expensive, while not facilitating the optimum distribution of foods or comestibles within the container to allow for a more uniform temperature distribution therethrough during cooking with microwave energy.
Watkins U.S. Pat. No. 4,416,906 discloses a microwave food heating container having a central raised core in the container bottom to essentially distribute the food contained therein about an annulus to improve upon the uniform heating thereof. As in the other above-mentioned patents, there is no optimum distribution of the food within the container so as to allow for a greater efficiency during cooking and a degree in the uniformity of the temperature which will meet the demands of the technology for cooking with microwave energy.
Isakson, et al. U.S. Pat. No. 4,640,838 describes a vapor-tight microwave oven package incorporating a vent enabling the escape of steam or vapor which is generated during cooking, and does not provide for an optimum distribution of foods within a generally rigid microwaveable container to attain uniform temperatures during microwave cooking or heating of the food contents of a container.
Levendusky, et al. U.S. Pat. No. 4,560,850 discloses a microwave container with a cover incorporating a port for the release of steam, and with a raised container bottom to distribute the foods therein for more even cooking or heating. This structure also fails to provide for the optimum dispersion of a food within a specially configured container and does not allow for an adequately uniform temperature distribution through the food as it is cooked by microwave energy with a resultant higher degree of efficiency.
Although various measures have been undertaken to improve upon efficiency and temperature uniformity of microwave cooking, they have not proven to be entirely adequate, especially when used for prepackaged, single-serve applications. Many single-serve microwavable trays are relatively flimsy, making it difficult for a consumer to remove a tray containing hot items from the microwave without experiencing some discomfort. Moreover, many prior art trays require expensive container constructions.
Single-serve containers often require specially designed wrappers or packaging cartons to display nutritional information, ingredients, and heating instructions. These wrappers and packaging cartons can become destroyed or separated from the carton upon use, requiring separate packaging materials and instructions for each microwave serving. This extraneous packaging material increases the cost to the consumer. Prior art trays also incorporate inefficient designs which do not adequately utilize the retail shelf space or the volume of the shipping cube.
In view of the shortcomings set forth above, it is an object of the invention to provide an improved microwave food package, which minimizes material requirements, locks multiple containers in a paperboard sleeve, and optimizes the shipping cube and retail shelf space. It is also an object of the invention to facilitate removal of the tray from the microwave when the tray contains hot materials.
The invention includes a container for use in microwave heating. The container includes a bottom, a sidewall extending upwardly from the bottom and terminating at a top end, and a flange extending from the sidewall opposite the bottom. The flange includes a rim section configured to receive a sealing film and a recessed section including a plurality of handles. A pair of catch members are located between the plurality of handles. The catch members extend radially outwardly on opposed sides of the container.
In another embodiment, the invention includes a food package assembly comprising a first tray including a bottom, a sidewall extending upwardly from the bottom and terminating at a top end and a flange extending from the sidewall opposite the bottom. The flange includes a rim section configured to receive a sealing film and a recessed section extending from the rim section. The recessed section terminates in a pair of opposed lateral edges and a pair of opposed longitudinal edges, wherein each of the opposed longitudinal edges intersect with a lateral edge at a corner, wherein each corner contains a handle. An outwardly extending catch member is disposed between the handles on each of the lateral edges. A sealing film is attached to the rim section. A sleeve for holding the tray including a sleeve top and a sleeve base. The sleeve base contains an aperture having a port, wherein the catch member is disposed through the port.
Yet another aspect of the invention includes a method of preparing food for subsequent sale. The method includes the steps of providing a container including a bottom, a sidewall extending upwardly from the bottom and terminating at a top end, the sidewall defining an interior, and a flange extending from the sidewall opposite the bottom. The flange includes a rim section configured to receive a sealing film, and a recessed section extending from the rim section. The recessed section terminates in a pair of opposed lateral edges and a pair of opposed longitudinal edges, wherein each of the opposed longitudinal edges intersect with a lateral edge at a corner, wherein each corner contains a handle. A catch member is disposed on each of the lateral edges, between the handles. The method also includes the steps of positioning food in the interior of the container, attaching a sealing film to the rim section, providing the sleeve including a sleeve top and a sleeve base, wherein the sleeve base contains an aperture having a port and placing the tray in the sleeve so that the catch member is at least partially disposed through the port.
In a preferred embodiment, the invention includes a food package kit including a plurality of trays having a bottom, a sidewall extending upwardly from the bottom and terminating at a top end, and a flange extending from the sidewall opposite the bottom. The flange includes a rim section configured to receive a sealing film and a recessed section extending from the rim section. The recessed section terminates in a pair of opposed lateral edges and a pair of opposed longitudinal edges, wherein each of the opposed longitudinal edges intersect with a lateral edge at a corner, and each corner contains a handle. The trays also include an outwardly extending catch member disposed between the handles on each of the lateral edges. Sealing film is adapted to be attached to the rim section. The kit also includes a sleeve adapted to contain the trays completely therein. The sleeve includes a sleeve top, a first depending sleeve side, a second depending sleeve side and a sleeve bottom, wherein the tray is completely disposed within the sleeve by frictional force between the tray and the sleeve.
In another alternative embodiment, the invention includes a food package kit having a first tray and a second tray. Both the first tray and the second tray include a bottom, a sidewall extending upwardly from the bottom and terminating at a top end, and a flange extending from the sidewall opposite the bottom. The flange includes a rim section configured to receive a sealing film and a recessed section extending from the rim section. The recessed section terminates in a pair of opposed lateral edges and a pair of opposed longitudinal edges. Each of the opposed longitudinal edges intersect with a lateral edge at a corner, wherein each corner contains a handle. An outwardly extending catch member is disposed between the handles on each of the lateral edges. A sealing film is adapted to be attached to the rim section. The kit also includes a sleeve adapted to hold the first tray and the second tray completely therein using only frictional force. The sleeve includes a sleeve top, a first depending sleeve side, a second depending sleeve side and a sleeve bottom. The first tray and the second tray are disposed within the sleeve by frictional force between the first tray, the second tray, and the sleeve.
In yet another alternative embodiment, the invention includes a method of preparing food for subsequent sale. The method includes the steps of providing a container having a bottom, a sidewall extending upwardly from the bottom and terminating at a top end, the sidewall defining an interior and a flange extends from the sidewall opposite the bottom. The flange includes a rim section configured to receive a sealing film and a recessed section extending from the rim section. The recessed section terminates in a pair of opposed lateral edges and a pair of opposed longitudinal edges. Each of the opposed longitudinal edges intersect with a lateral edge at a corner and each corner contains a handle. A catch member is disposed on each of the lateral edges, between the handles. The method also includes the steps of dispensing food in the interior of the container, attaching a sealing film to the rim section, providing a sleeve including a sleeve top, a first depending sleeve side, a second depending sleeve side and a sleeve base. In accordance with the method, the tray or a plurality of trays are placed completely within the sleeve so that frictional force between the tray and the sleeve keeps the tray or trays inside the sleeve.
The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
A microwavable food container 10 in accordance with the invention is shown in
Handles 18 extend from the corners of flange 16. Sidewall 14 and flange 16 are uniquely configured to provide torsional support when container 10 is lifted. Container 10 can incorporate different wall thicknesses. In one embodiment, container 10 has a wall thickness from about 0.02 to about 0.05 inches.
Throughout this specification, directional terminology, such as “top,” “bottom,” “upwardly,” “downwardly,” “above,” “below,” etc. is used with reference to the preferred upright orientation of container 10 in
With reference to
Bottom 12 defines opposing longitudinal sides 24 and opposing lateral sides 26, as best shown in the top plan view of
As shown in
In an alternative embodiment, bottom 12 may be concaved upwardly or inwardly relative to interior 20 to enhance microwave interaction with food items contained within container 10. In yet another embodiment, bottom 12 may include a load bearing surface around the perimeter of bottom 12. This configuration promotes the overall stability of the container.
Sidewall 14 is continuous, extending from bottom 12. In this regard, sidewall 14 is defined by a base section 40, an intermediate section 42 and an upper section 44. Base section 40 extends from bottom 12. Intermediate section 42 extends between base section 40 and upper section 44. Finally, upper section 44 terminates in flange 16.
Base section 40 extends radially outwardly and upwardly from bottom 12. In particular, base section 40 is curved in transverse cross-section (or “transversely curved”). With respect to the central axis of container 10, base section 40 forms a convex curve. Moreover, base section 40 defines a transverse, cross-sectional radius in the range of from about 0.25 to about 1.0 inch. However, a radius in the range of from about 0.4 to about 0.6 inch promotes the overall stability and torsional resistance of container 10.
Intermediate section 42 extends generally upwardly from base section 40, and is linear in transverse cross-section. As shown in
Finally, upper section 44 extends from intermediate section 42, and defines a collar 48 and a stacking wall 50. Collar 48 extends radially outwardly from intermediate section 42. Stacking wall 50, in turn, extends generally upwardly from collar 48 and terminates at flange 16. In one embodiment, stacking wall 50 defines, in transverse cross-section, a slight inward taper from bottom to top, relative to the central axis. With this configuration, upper section 44 promotes stacking of another, similarly formed container (not shown) within container 10, but prevents the second container from entirely nesting within container 10, with collar 48 of the second container resting on flange 16. If the second container were allowed to fully nest within container 10, frictional forces would prevent easy disassembly of the second container from container 10.
An additional feature of sidewall 14 is best illustrated by the longitudinal or top plan cross-sectional view of
With reference to
Recessed section 62 extends from edge 66 of rim section 60 opposite sidewall 14. As depicted in
Recessed section 62 preferably extends an appreciable distance downwardly relative to outer surface 64 of rim section 60. In one embodiment, recessed section 62 of the invention has a downward extension (relative to the outer surface 64) in the range of from about 0.1 to about 0.2 inch. It is believed that this relatively small downward extension, within the critical range, contributes to overall stability of container 10 while reducing the amount of space required to store nested empty containers 10 and full packaged containers 10.
Flange 16 provides a relatively large spacing between recessed section 62 and sidewall 14, thereby dissipating the amount of heat transferred from sidewall 14 to recessed section 62 that might otherwise be touched by a user, while not noticeably increasing manufacturing costs. For example, when container 10 containing a food substrate was heated for 2 minutes using a 1000 watt microwave oven, the temperature of sidewall 14 was found to be about 140° F. (60° C.). The temperature of flange 16 was about 100° F. (38° C.). However, the temperature of the grips 66 was less than 100° F. (38° C.), enabling a person to remove container 10 safely from the microwave oven.
An additional feature of flange 16 is best illustrated by the longitudinal or top plan view of
With reference back to
Both of flange 16 and collar 48 define compound curves as previously described. This characteristic has been found to provide container 10 with an elevated level of torque resistance when a lifting force is applied at a single point along corners 22. Following heating, container 10 is preferably lifted by a user (not shown) via handles 18. In the event the user inadvertently lifts container 10 with a single hand, grasping a handle 18 at one of corners 22, the compound curvature nature of flange 16 and collar 48 resist deflection or bending of the container 10 due to a weight of the contained food item (not shown).
With reference to
Sleeve 100 is designed to hold one or more containers 10 firmly in place within sleeve 100 to form a sleeve assembly 200 as shown in
With reference to
Apertures 420, 422, 424, and 426 generally comprise identical configurations. Therefore, the only the configuration of aperture 426 will be discussed in detail. Aperture 420 is particularly suitable for applying pressure to catch members 80 to create a frictional force that assists in holding containers 10 and 260 into sleeve 410. Aperture 426 includes a generally hourglass shape with narrow portion 480 between wide portions 482 and 484. The center of aperture 426 includes a diamond-shaped center portion 486. Slits 488 and 490 are formed in sleeve 410 on opposing sides of center portion 486. Sleeve 410 also includes crease 492 that extends from the end of slit 488 to wide portion 484, crease 494 that extends from the end of slit 490 to wide portion 484, crease 496 that extends from the end of slit 490 to wide portion 482, and crease 498 that extends from the end of slit 488 to wide portion 482. Creases 492, 494, 496, and 498 generally comprise an arc configuration facilitate deformation of sleeve 410 around aperture 426. However, creases 492, 494, 496, 498 may form a variety of patterns including straight, wavy or zigzagged while remaining within the scope of the invention.
As shown in
In a preferred embodiment, the portion of flaps 502, 504, 506, and 508 adjacent to aperture 426 push outwardly as catch members 80 of trays 10 and 260 move through aperture. Once catch members 80 are in a desired position relative to sleeve 410, flaps 502, 504, 506, 508 move back to a position that is planar with side 416.
Sleeve 940 is shown in
Assemblies 200 and 800 in
Assemblies 200, 700, 800, and 900 are used to package foods for preparation by a consumer in a microwave oven, but are not necessarily limited to foods to be microwaved. During packaging, the food distributor places food products in the various containers 10, 220, 240, and 260. A heat seal (not shown) is placed over each of the containers and is hermetically sealed to outer surface 64 to provide an air tight compartment in interior 20. Next, sealed tray 10 is placed in sleeve 100 by sliding the bottom of container 10 through opening 110 so that the lower portion of flange 16 of container 10 catch members on base 102 of the sleeve. Another container 220 is inserted into opening 112 in similar fashion. Next, container 260 is placed on top of container 10 such that flange 16 of container 10 touches flange 16 of container 260. Moreover, container 240 is placed on top of container 10 such that flange 16 of container 10 touches flange 16 of container 240. After the trays are in place, as described, panels 104 and 108 are folded together over trays 240 and 260. In this configuration, catch members 80 of containers 10 extend at least partially through ports 120 or 122 to lock the trays 10, 220, 240, and 260 in sleeve 100. Once the top panel 108 is secure against panel 212, assembly 200 is ready for distribution in the marketplace. This configuration of assembly 200 provides sufficient interference to prevent any one of containers 10, 220, 240, and 260 from inadvertently sliding out of the assembly 200 during distribution, storage, while on a store shelf, or in a consumer's home.
After assembly 200 is packed, sleeve 100 protects containers 10, 220, 240, and 260 and insures that the heat seal remains sealed to flange 16. It also helps provide a tamper-evident package that displays nutritional information, ingredients, heating directions, and other information. Sleeve 100 also safeguards the containers by acting as a protective layer during shipping and also when the tray is displayed on the shelf, freezer, refrigerator, or other display area. For this reason, sleeve top 108 is typically a continuous piece that is free of any apertures.
Once a customer purchases assembly 200, there is no need to remove the container from sleeve 100 until container 10 and its contents are ready to be cooked. After assembly 200 is purchased, the consumer places the assembly in a home pantry, freezer or refrigerator until the consumer wishes to cook the food in container 10.
When the consumer desires to prepare the food in container 10 for consumption, the consumer takes the assembly and separates it along perforation 270. Perforation 270 may include a zip strip, or other apparatus to separate assembly along line 270. Next, one container is removed from the assembly by tearing sleeve 100 or bending the sleeve to a shape in which catch members 80 can slide out of ports 120.
The container 10 and sleeve 100 of the invention provides a marked improvement over previous designs. More particularly, the container 10 is well suited for pre-made food packaging and heating applications, in that a thermoformed plastic is utilized such that overall costs are minimized. To this end, a wide variety of food items can be contained and heated within the container, including meat products, pasta products, vegetable products, combinations of meat/pasta/vegetable, desserts, grain based products and cereals, etc. Further, container 10 provides improved heat deflection at handles 18 and is essentially reinforced against torsional forces generated when the container is lifted by a single hand following heating within an oven.
With reference to
The general operation of tabs 430 and 432 will be discussed with reference to tab 432, although tab 430 functions in a similar fashion. For example, to remove container 260 from assembly 400, a user pulls on tab 432 to remove tab 432 from the general plane containing sleeve top 418. User then pulls tab 432 in a direction toward side 434 causing sleeve top 418 to tear along perforation lines 436 and 438. When tab 432 is completely separated from sleeve top 418, the distance between margins 440 and 442 increases. The increased distance between margins 440 and 442 reduces the frictional force holding container 260 inside sleeve 410 and enables a user to remove container 260 from sleeve 410 relatively easily.
The individual scores that are shown to make up perforation lines 436 and 438 include a portion that is parallel to margins 440 and 442 and a portion that is inwardly skewed relative to margins 440 and 442. This configuration is desirable for directing and controlling the tear of sleeve top 418 between lines 436 and 438. It is important to note, however, that lines 436 and 438 can comprise a wide variety of configurations relative to one another. For example, lines 436 and 438 may be parallel to or skewed relative to one another or margins 440 and 442. Alternatively, sleeve 410 may be fabricated without tabs 430, 432, and lines 436, 438 as shown in
Tabs 430 and 432 are shown to comprise a generally half-circular configuration. It is important to recognize, however, that tabs 430 and 432 may comprise a variety of configurations while remaining within the scope of the invention, including, but not limited to oval, polygonal, or irregularly shaped.
Although the invention has been described with reference to preferred embodiments, those of ordinary skill in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the invention.
Number | Name | Date | Kind |
---|---|---|---|
4416906 | Watkins | Nov 1983 | A |
4486640 | Bowen et al. | Dec 1984 | A |
4560850 | Levendusky et al. | Dec 1985 | A |
4640838 | Isakson et al. | Feb 1987 | A |
4704510 | Matsui | Nov 1987 | A |
5266763 | Colombo | Nov 1993 | A |
6559431 | Hopkins | May 2003 | B2 |
6615985 | Foreman | Sep 2003 | B1 |
20040035867 | Schultz et al. | Feb 2004 | A1 |
Number | Date | Country | |
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20060254943 A1 | Nov 2006 | US |