Patent Application
20240130497
The present invention relates to a lunchbox for storing, transporting, and heating solid, paste-like or liquid foodstuffs, particularly foodstuffs prepared for consumption.
Lunchboxes for storing and transporting foodstuffs that are to be consumed in transit or at the workplace have been in use for many decades. Two-part boxes made of metal or plastic are known with a hinged lid or an attachable lid with a large lower part for a main meal or with overlapping upper and lower parts of approximately equal size for bread or the like. In retail trade, one- or two-part disposable containers, usually consisting of foamed plastic, are used primarily to provide ready-to-eat portions of fruits, vegetables, or ready-made meals.
A hinged container, designed in such a way that items cannot fall out when an upper shell is opened, is known from DE 202013010997 U1. The hinged container consists of an upper shell and a lower shell, which are hinged together on one longitudinal side. A snap closure is provided on the opposing longitudinal side. The upper shell is provided with an upper inner lid and the lower shell with a lower inner lid, so that the two internal volumes can be completely closed independently of each other. On the side opposite the hinge of the inner lid, a lid closure in the form of a snap-in lug is provided in the upper shell and the lower shell.
Another plastic lunchbox for storing foodstuffs is disclosed in DE 10157494 B4. It consists of a container with side walls, abase, and a molded-on lid. An additional chamber is arranged on the underside of the container, which can be closed with an additional lid. The lid and additional lid are connected to the container by a film hinge.
Another container with a lid for storing foodstuffs contains an exothermic heating element according to EP 0412159 B1. The container comprises an upper inner container for the materials to be heated and a lower inner container located therebelow containing water and an exothermic material, wherein the lower inner container is provided with a cover. The container also comprises a device which can be operated from the outside for contacting the exothermic material with the water. The cover of the lower inner container is steam-permeable but impermeable to the exothermic material.
The water and exothermic material are provided in separate packets which can be torn open separately.
This type of solution is costly and only suitable for stationary operation.
A transportable lunchbox is known from WO 2011/112284 A1. The lunchbox comprises an upper shell and a lower shell, which are connected together in hinged fashion on one longitudinal side, wherein a closure is provided on the opposing longitudinal side. A pivotable separation shell is also provided so that an upper and lower chamber are formed to hold edibles. A shell can be inserted into the lower chamber, which can also be loaded with a cooling or heating gel in order to be able to temporarily maintain the edibles at a certain temperature.
GB 2056264 A shows a conventional lunchbox for keeping foods warm for use in kitchens or in catering with a lid that is attached to the box by means of a hinge and can be locked by means of a safety catch. A power connection is clearly provided, in which the heating element is a conventional heating wire that only permits heating of foods from below.
In another heatable lunchbox, an inside container that can be closed with an attachable lid can be inserted into the lower shell. Indentations for cutlery are formed into the upper shell. The lower shell is provided with a power connection for a heating element in the lower shell, which is arranged in a foam insulation layer. The heatability of foodstuffs found in the inner container is limited or protracted.
US 2015/0245723 A1 discloses drinking vessels that can be actively heated or cooled. They have a cylindrical outer sleeve with a closed bottom in the form of a partition. The upper cover surface can be closed with a lid. A heatable and double-walled cylinder (inside cylinder) is provided in the outer sleeve.
Power is supplied by means of integrated batteries in a double bottom beneath the partition, which also contains a controller for the batteries.
One aspect of the invention relates to a lunchbox that overcomes the disadvantages of the prior art and that is easy to handle.
The lunchbox according to the invention includes a lid and a housing that can be connected to each other. It comprises an electric heating element, a device for supplying power and controlling the supply of power and operating modes, and a sensor arrangement for temperature control of the heating element.
Preferred embodiments of the invention are disclosed herein.
The lunchbox according to the invention is suitable for storing, transporting, and heating or cooling solid, paste-like, or liquid foodstuffs, particularly foodstuffs, particularly ready-to-eat foodstuffs. The foodstuffs can also be in flat plastic bags, glass containers or the like.
The lunchbox according to the invention can thus be used flexibly. The lunchbox is applicable for foods for adults, children or babies.
The invention is further described below in an embodiment example with reference to a drawing. In the drawing
A lunchbox 20 according to the invention (
Instead of snap-in closure 4, a film hinge can also be provided (molded on one longitudinal side) or also a pivot hinge, which is fastened to the upper and lower shells, or the like. The upper shell 1 can thereby be opened.
Upper shell 1 and lower shell 2 lie flat against each other in a separation plane and possibly overlap with an overhang of the upper shell 1.
A power connection socket 5 is provided on a side wall of the lower shell 2, in which it can be designed in the form of a conventional plug or as a USB connection in order to establish a connection to a charging station 21 or power supply. Alternatively or additionally, such a power connection socket 5 can also be provided in the upper shell 1.
Alternatively or additionally, flat rechargeable batteries can also be arranged in the lower shell 2.
An LED 6 is also arranged on the opposite side wall of the lower shell 2 as a status indicator (heating) and possibly as a temperature indicator 23. An unspecified pressure equalization element for extracting warm air and water vapor may also be disposed in the upper shell 1.
The circumferential edge areas of the upper shell 1 and lower shell 2 are correspondingly shaped to function as a seal.
At least one insertable or removable shell 9 to accommodate food to be heated or cooled can also be a component of the lunchbox 20.
The shell 9 is formed, for example, from an aluminum material or stainless steel 0.5 mm thick and arranged in lower shell 2. The shell 9 has an L-shaped angled edge area 8, wherein a seal can be positioned between the edge area 8 and the lower shell 2.
The shell 9 can also be flat, for example, to accommodate liquids in flat dispensing packets of, for example, 180 mL capacity. This also allows breast milk to be sterilely heated and kept warm at, e.g., 37° C., without the need for a water bath, and also much more quickly than in a bottle.
In an appropriate embodiment of the lunchbox, cooling of the dispensing packet or the like before reheating would also be possible, for example, by means of a Peltier element.
The lower shell 2 can also be designed with higher walls, in a manner not shown, so that several shells 9 can be arranged one above the other.
The shell 9 can be simply removed from the lower shell 2 for cleaning or other purposes. In another embodiment, a fixed arrangement of shell 9 and lower shell 2 would be possible, for example, by means of adhesive bonding, etc.
Insertable or fixed shells 9 without thermal insulation are also possible.
The design and shape of the shell 9 and the lower shell 2 are adapted or matched to each other. Consequently, differently shaped shells 9 can be used and inserted into the lower shell 2.
The height of the lunchbox 20 can be adjusted to the height of shell 9, so that flat lunchboxes can be produced in addition to tall ones.
Thermal insulation 11, for example, made of a PUR integral foam, can be provided between the inner wall of lower shell 2 and shell 9, wherein, in the example, a sensor-controlled electric heating element 12 with a heating film can be positioned between this and shell 9. This enables precise temperature control of the heating (or cooling). The thermal insulation 11, however, could also be formed from a Keraguss S-molded article, an aerogel molding or an EPS molding, air or vacuum.
Thermal insulation 11 and the heating film can cover the bottom area of the shell 9 or also at least partially enclose the side walls of the shell 9.
Further, he inside of the upper shell 1 may also be provided with such thermal insulation 11 and a heating element 12.
The connection between the power connection socket 5 and a control electronics 13 as well as to the heating element 12 is made via cable connections, not shown.
The control electronics 13 are arranged, for example, on a flat circuit board, which in turn is plugged into the inner wall of the lower shell 2 to save space. The control electronics 13 include the electronic control, a safety switch, and a load switch. The electronic control 13 should include at least an analog or digital temperature sensor 30, a heating switch (thermal switch 31) and the output for the LED 5, and the temperature indicator 23.
The electronic control can also permit various heating modes, for example, lower and/or upper heating.
The electronic control 13 can also communicate with an external control device 22, for example, a smartphone 24, and be controlled via an app.
Alternatively or additionally, haptic buttons, sensor buttons and/or a display may be provided on the lunchbox 20 itself to allow mode and temperature settings to be made thereon.
The sensors 30, 31 are preferably arranged close to the outer edge of shell 9 (
An optical sensor, a camera or a thermal imaging camera can also be arranged, advantageously in the upper shell 1 above shell 9, with which the food can be monitored.
In an additional embodiment, the heating element 12 can also have a zonal design, wherein each zone can be assigned a sensor 30, 31. This permits heating (cooling) to different target temperatures in the individual zones.
In the example, the heating element 12 consists of a metallic heating film, which is embedded between two silicone layers for electrical insulation. However, Kapton heating films, polyester heating films, ceramic heating elements, or contact heating elements can also be used.
The power supply can range from 5 V to 240 V, including the typical tolerances. For example, at 5 V or 12 V DC no special safety measures need be provided. In an embodiment with 230 VAC, the shell 11 must either be grounded or the aforementioned double electrical insulation must be applied.
In selecting the connection variants, the current rating, temperature, and resistance to cleaning agents must be taken into consideration.
The electrical connections are preferably waterproof
The heating power of the heating film should be at least approximately 20-150 W in order to allow heating of foods as required up to about 160° C. Depending on the food, smaller or larger heating powers may also be permissible, wherein the values are also dependent on whether a heating element is provided only in lower shell 2 or also in the upper shell 1. When a heating element is arranged in the upper shell 1, its heating capacity is normally less than that in lower shell 2.
The lunchbox 20 is connected to the power source to heat a food item and the start button, which actuates the LED 6. The LED 5 indicates, when lit, the heating process over a time period preset in control electronics 12. In addition, the heating can also be displayed as a colored temperature indicator 23 by means of an additional LED.
After the heating period has elapsed, the control electronics switches off the heating film, which turns off the LED 5.
Other operating modes can be programmed by means of the control device 22 and an app.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IB2021/051597 | 2/26/2021 | WO |
