Insulated Lunch Box

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

BACKGROUND

This disclosure generally relates to an insulated lunch box comprising: (1) a double-walled, insulated base; (2) an insert; and (3) a double-walled, insulated lid. The insulated lunch box is designed to store a hot pack or cold pack in the double-walled, insulated base between the double-walled, insulated base and the insert. Some embodiments may also allow for storage of a hot pack or cold pack in the double-walled, insulated lid between the double-walled, insulated lid and the insert.

For purposes of this disclosure, unless otherwise specified, “double-walled” means that something has two layers of a material with an insulated layer in between (“insulated” is defined below). Double-walled technology is well-known in the art. Stainless steel is the most commonly used material for double-walled food and liquid containers, but any suitable material as understood by a person skilled in the art may be used by embodiments of the instant disclosure.

“Stainless steel” as used in the present disclosure includes all types of stainless steel including, without limitation, any food grade stainless steel, which are typically in the 200 series, 300 series, or 400 series (e.g., grade 302 stainless steel, grade 304 stainless steel, 18/10 stainless steel,18/8 stainless steel, 18/0 stainless steel, grade 316 stainless steel, grade 420 stainless steel, grade 430 stainless steel, grade 434 stainless steel, grade 444 stainless steel) or duplex stainless steel (grades 2205 and 2507). For embodiments using non-magnetic grades of stainless steel, a certain subset of those embodiments may utilize thermal treatment or work hardening to partially magnetize the stainless steel to facilitate magnetic attachment of such stainless steel.

For purposes of this disclosure, unless otherwise specified, “insulated” shall include vacuum insulation and air insulation. Vacuum insulation and air insulation are well known in the art. For the sake of completeness, a brief description is provided, but this brief description is not intended to be limiting on the understanding of a person of skill in the art. Vacuum insulation is a type of insulation that uses a vacuum to create a barrier between two layers of material preventing heat transfer between them by (i) removing air and gas molecules, which are materials that could conduct heat between the walls; and (ii) reflecting and absorbing radiant heat (vacuum space acts as a barrier preventing radiant heat from entering or escaping the container). Air insulation relies on air's poor thermal conductivity to block heat.

For purposes of this disclosure, a “hot pack” and “heat pack” are interchangeable terms and refer to an object that is used to provide heat. Specifically in the context of this disclosure, a hot pack/heat pack is used to provide heat to the contents of the insulated lunch box. Different types and contents of hot packs are known in the art, which is incorporated herein by reference.

For purposes of this disclosure, a “cold pack” and “ice pack” are interchangeable terms and refer to an object that is used to make or keep an object cold. Specifically in the context of this disclosure, a cold pack/ice pack is used to make or keep the contents of the insulated lunch box cold. Different types and contents of cold packs are known in the art, which is incorporated herein by reference.

As would be understood by a person of skill in the art, only certain materials may be used in products that may come into contact with food. In the United States, the United States Food and Drug Administration (FDA) regulates these “Food Contact Substances” and has a database listing all approved Food Contact Substances under Title 21 of the Code of Federal Regulations (CFR). Other countries/collections of countries (e.g., European Union) also have similar regulatory frameworks and lists (e.g., the European Union has a list of “Food Contact Materials” that must comply with Regulation (EC) No 1935/2004). When this disclosure uses the term “food safe” or a similar term, it refers to a substance that is suitable for contact with food.

Thermal conductivity (the symbol for which is a lowercase k or Greek letter lambda) is a measure of a material's ability to pass heat through it. Materials with high thermal conductivity are capable of effectively transferring heat and readily take up heat from their environment; whereas, materials with low thermal conductivity resist heat flow and obtain heat slowly from their surroundings. Thermal conductivity is measured in Watts per meter per degree Kelvin (W/m⋅K) following the S.I (International System) guidelines.

Insulated lunch boxes known in the art are not able to effectively keep food warm or cold. Lunch boxes that are battery powered are heavy, expensive, heat food too much (or not enough), and many schools prohibit them for use by children. There is thus a need in the art for the insulated lunch box of the present disclosure, which is well insulated and contains one or more hot or cold packs.

BRIEF SUMMARY

This disclosure generally relates to an insulated lunch box comprising: (1) a double-walled, insulated base; (2) an insert; and (3) a double-walled, insulated lid. The insulated lunch box is designed to store a hot pack or cold pack in the double-walled, insulated base between the double-walled, insulated base and the insert. Some embodiments may also allow for storage of a hot pack or cold pack in the double-walled, insulated lid between the double-walled, insulated lid and the insert.

The insulated lunch box may be any size or shape, and the insert may be designed to have one or more food containers and are made using food safe materials. The double-walled, insulated base may be designed with our without a lip to accommodate insertion of the insert.

The insulated lunch box of the present disclosure efficiently utilizes its self-contained heat or cold source(s) to keep food warm or cold.

DETAILED DESCRIPTION

This disclosure generally relates to an insulated lunch box comprising: (1) a double-walled, insulated base; (2) an insert; and (3) a double-walled, insulated lid. The insulated lunch box is designed to store a hot pack or cold pack in the double-walled, insulated base between the double-walled, insulated base and the insert. Some embodiments may also allow for storage of a hot pack or cold pack in the double-walled, insulated lid between the double-walled, insulated lid and the insert.

The insulated lunch box of the present disclosure may take any shape, but expressly contemplated embodiments include circles, ovals, squares, squircles (squares with rounded corners), rectangles, rounded rectangles (rectangles with rounded corners), diamonds, trapezoids, pentagons, hexagons, heptagons, octagons, nonagons, and decagons.

The insulated lunch box of the present disclosure may be of any size. Embodiments may be (i) small enough for a snack for a child, (ii) big enough to accommodate multiple meals for multiple people; or (iii) somewhere in between (i) and (ii).

The double-walled, insulated base forms the bottom of the insulated lunch box. Unlike other lunch boxes where the base of the lunch box is used to store food, the double-walled, insulated base of this present disclosure is intended to hold a hot pack or cold pack. Some embodiments of the double-walled, insulated base may include a means for attaching a hot pack or cold pack to the inner portion of the double-walled, insulated base. The means for attaching described in this paragraph are known in the art, but snap fit joints, magnets, and latches or other physical means are expressly contemplated. Commercially available hot packs or cold packs may require modification (e.g., addition of a case) to be attached, and such modification would be understood by a person of skill in the art without undue experimentation.

The double-walled, insulated base may optionally include a lip or ridge on which the insert will rest or attach (i.e., some embodiments may just rest and other embodiments may attach). For embodiments where the insert is to be attached, any means known in the art may be utilized, but snap fit joints and magnets are expressly contemplated. The lip or ridge may run all the way around the double-walled, insulated base or it may only be at certain point(s) on the double-walled, insulated base.

For certain embodiments without a lip or ridge, the double-walled, insulated base may optionally have a slightly wider internal dimension at the top of the double-walled, insulated base as compared to the internal dimension at the bottom of the double-walled, insulated base so that the insert may be sized to stop higher or lower in the double-walled, insulated base.

The inserts of the present disclosure are designed to hold food and may be made of any food safe material. Without limiting the generality of the foregoing: (i) some embodiments may be made of stainless steel; (ii) some embodiments may be made of glass; (iii) some embodiments may be made of food safe plastic (e.g., high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polyethylene terephthalate (PET/PETE), food-grade polycarbonate (PC), acrylic, nylon, rigid PVC, or uPVC); (iv) some embodiments may be made of food safe silicone; and (v) some embodiments may be made of a combination of (i)-(iv) of the foregoing.

As explained above, the inserts are designed to be inserted into the double-walled, insulated base (optionally resting or attached to a lip or ridge on the double-walled, insulated base) and are used to hold food. The insert shall comprise one or more compartments for food, and there is no limit on the number of compartments, but embodiments with one, two, three, four, five, six, seven, eight, nine, ten, eleven, and twelve compartments are expressly contemplated. To illustrate how the insert is built, the insert itself shall be on substantially one geometric plane. The food compartments are depressions from that plane that run down towards the double-walled, insulated base. Using a two-inch cubical food compartment as a non-limiting example, the two-inch cubical food compartment will have (A) four walls that are each two inches deep (down from the plane of the insert towards the double-walled, insulated base) and are perpendicular to the plane of the insert and make right angles to one another and (B) one wall that is two inches by two inches that runs parallel to the plane of the insert and forms the fifth wall of the two-inch cubical food compartment at the bottom closest to the double-walled, insulated base. There is nothing where the sixth wall of the two-inch cubical food compartment would be (at the top, which is on the same plane as the insert) so that food can be added to the food compartment from above. For embodiments utilizing a combination of materials described in the paragraph above, it may be particularly advantageous to have embodiments where the walls of the food compartment are made of a material (or combination of materials) with a higher thermal conductivity than the rest of the insert. To illustrate, using the two-inch cubical food compartment introduced in this paragraph as an example, the four walls described in (A) and the fifth wall described in (B) shall be made of a material with a higher thermal conductivity than the rest of the insert. To continue this example, and to disclose one exemplary embodiment, the insert is made of HDPE plastic (thermal conductivity of 0.51 W/m⋅K) and the walls of the food compartment are made of grade 304 stainless steel (thermal conductivity of 16.2 W/m⋅K). Using materials with different levels of thermal conductivity has the benefit that more heat from the hot pack (or cold from the cold pack) will transfer to where the food is being stored. As another exemplary embodiment of an insert, the insert may be made entirely of grade 304 stainless steel but be wrapped in silicone (thermal conductivity varies based on the type of silicone but in any case is significantly less than the thermal conductivity of grade 304 stainless steel) such that the silicone covers (a) at least some, (b) most, (c) substantially all, or (d) all of the surface of the insert that is not part of a food compartment. The silicone cover may optionally be configured to allow for removal for cleaning and/or replacement and may be in one piece or more than one piece. A gasket may placed around the insert to create a tight seal between the insert and the inner walls of the double-walled, insulated base. The gasket may be made of any material, but a material with low thermal conductivity is used in preferred embodiments. Exemplary gasket materials include various rubbers and cork.

The food compartments of the insert may have grooves to allow for the insertion of optional dividers to divide the food compartment into sections. The optional dividers may be made of any food safe material, but stainless steel and food safe plastics (including those expressly disclosed above) are expressly contemplated.

The double-walled, insulated lid forms the top of the insulated lunch box. Some embodiments of the double-walled, insulated lid may include a means for attaching a hot pack or cold pack to the inner portion of the double-walled, insulated lid. The means for attaching described in this paragraph are known in the art, but snap fit joints, magnets, and latches or other physical means are expressly contemplated. Commercially available hot packs or cold packs may require modification (e.g., addition of a case) to be attached, and such modification would be understood by a person of skill in the art without undue experimentation. Other embodiments may have attachments on the double-walled, insulated lid for utensils or a paper towel, napkin, or other absorbent material (which may be used to clean your face or hands but also may be used to absorb condensation from inside the insulated lunch box). Certain embodiments of the present insulated lunch box may comprise one or more handles such as, for example (i) one handle on the top or (ii) one handle on each side.

The double-walled, insulated base and the double-walled, insulated lid may be combined together to form the disclosed insulated lunch box by any means known in the art. Without limiting the generality of the foregoing, draw latches and sliding latches are expressly considered because of their convenience and security. Hinges, to be mixed with at least one latch are also expressly considered. If only latches are used as a means for combining the double-walled, insulated base and the double-walled, insulated lid, then at least one latch should be used, but adding more latches would provide a more secure closure. Any number of latches may be used, but expressly disclosed embodiments include: (i) two latches opposite from one another in embodiments of the insulated lunch box in the shape of a circle or shape with four sides; and (ii) four latches, one on each side in embodiments of the insulated lunch box in the shape of a circle or shape with four sides. In embodiments utilizing latches and hinges, any number of latches and any number of hinges may be used, but two exemplary embodiments are expressly contemplated: (1) one hinge plus at least one latch; and (2) two hinges plus at least one latch.

Certain embodiments may comprise a removable protective bumper on the double-walled, insulated base to protect the double-walled, insulated base from scratches or other damage. The bumper also has an added benefit of adding friction to keep the insulated lunch box from sliding across a surface. Other embodiments may have cosmetic enhancements (e.g., sleeves or finishes) on the double-walled, insulated base that achieve the same purpose.

The Examples provided below are provided as exemplary embodiments only and are not intended to limit the scope of disclosure above.

EXAMPLE 1

The insulated lunch box of this Example 1 comprises: (i) a double-walled, insulated base that is a rounded rectangle that has internal dimensions of 8 inches long by 6 inches wide by 3 inches deep; (ii) an insert that is a rounded rectangle that is approximately 8 inches long by approximately 6 inches wide by 0.25 inches deep (the length and width dimensions are just slightly smaller than the internal dimensions of the double-walled, insulated base to allow for a snug fit) and has two rectangular food compartments (the details of which are described below); and (iii) a double-walled, insulated lid that is a rounded rectangle that has internal dimensions of 8 inches long by 6 inches wide by 2 inches deep. The double-walled, insulated base is connected to the double-walled, insulated lid with a hinge at the back and has one draw latch on the front. Both the double-walled, insulated base and the double-walled, insulated lid have a snap fit holster to hold a hot pack (or cold pack).

The portion of the insert that is not the food containers is made of HDPE, and the food containers are made of grade 304 stainless steel. A rubber gasket is placed around the insert to create a tight seal between the insert and the inner walls of the double-walled, insulated base. The first food container is 4 inches long by 5 inches wide by 2 inches deep and is placed approximately 0.5 inches away from the left edge of the insert, approximately 0.5 inches away from the top edge of the insert, and approximately 0.5 inches away from the bottom edge of the insert. The left edge of the second food container is approximately 0.5 inches away from the right edge of the first food container, and the second food container is 2.5 inches long by 5 inches wide by 2 inches deep. The second food container is approximately 0.5 inches from the top of the insert, approximately 0.5 inches from the bottom of the insert, and approximately 0.5 inches away from the right edge of the insert.

The insert fits snug in the double-walled, insulated base and is inserted down until touching the hot pack (or cold pack) at the bottom of the double-walled, insulated base. As would be understood by a person in the art, if the double-walled, insulated base had a slightly smaller interior dimension at the bottom than the top, the size of the insert could be adjusted to fit at different spots in the double-walled, insulated base.

All dimensions and directions used in this Example 1 are as if looking straight down at the insert from above. The length dimension runs left to right. The width dimension runs top to bottom. The depth dimension runs down away from the surface.

EXAMPLE 2

The insulated lunch box of this Example 2 comprises: (i) a double-walled, insulated base that is a squircle (square with rounded corners) that has internal dimensions of 3 inches deep and 7 inches long by 7 inches wide above a lip built into the double-walled, insulated base, which decreases to 6.5 inches long by 6.5 inches wide at and below the 0.25 inch lip, which is all the way round the squircle; (ii) an insert that is a squircle that is approximately 7 inches long by approximately 7 inches wide by 0.25 inches deep (the length and width dimensions are just slightly smaller than the internal dimensions of the double-walled, insulated base to allow for a snug fit just above the lip of the double-walled, insulated base) and has one squircle food compartment (the details of which are described below); and (iii) a double-walled, insulated lid that is a squircle that has internal dimensions of 7 inches long by 7 inches wide by 1 inch deep. The double-walled, insulated base is connected to the double-walled, insulated lid with four draw latches, one centered at the midpoint of each side of the squircle. The double-walled, insulated base has a magnet to be attached to a hot pack (or cold pack), which has been modified to add a case with a magnet on the bottom.

The insert is made entirely of grade 304 stainless steel, and a silicone wrap is placed over the portions of the insert not comprising the food compartment. A cork gasket is placed around the insert to create a tight seal between the insert and the inner walls of the double-walled, insulated base. The grade 304 stainless steel where touching the lip is treated to partially magnetize it.

The food container of the insert is 6 inches long by 6 inches wide by 2 inches deep and is placed approximately 0.5 inches away from the left edge of the insert, approximately 0.5 inches away from the top edge of the insert, approximately 0.5 inches away from the bottom edge of the insert, and approximately 0.5 inches away from the right edge of the insert. There is approximately 1 inch between the bottom of the food container and the double-walled, insulated base to allow room for a hot pack (or cold pack). The food container has grooves at the midpoint of the food container (from the left to right direction) wherein a stainless steel insert can be inserted to split the area of the food container in half.

All dimensions and directions used in this Example 2 are as if looking straight down at the insert from above. The length dimension runs left to right. The width dimension runs top to bottom. The depth dimension runs down away from the surface.