Patent Publication Number: US-2023146911-A1

Title: Temperature-conserving containers

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims the benefit of U.S. Provisional Application No. 63/277,622, filed Nov. 10, 2021, which is hereby incorporated by reference in its entirety. 
    
    
     FIELD 
     The present disclosure relates to kitchen serving instruments, and particularly to insulated kitchen serving instruments. 
     BACKGROUND 
     Maintenance of food at a desired temperature for a desired amount of time can be an important task, in situations including in households, restaurants, and the hospitality industry. It may be important for appeal, taste, or health reasons to maintain food or drink near a given temperature until consumption. Further, applications in industries including, inter alia, the sciences to healthcare, can require various gases, liquids, and items to be maintained at or near a given temperature for a desired duration. 
     SUMMARY OF THE INVENTION 
     This Summary is provided to introduce a selection of concepts that are further described herein below in the Detailed Description. This Summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter. 
     In non-limiting examples disclosed herein, a lid may be configured for a temperature-conserving container having an opening defining an inner surface of the opening and a top rim. The lid may include a bottom wall, a side wall formed around a perimeter of the bottom wall, a top wall connected to the side wall, and an insulative cavity between the top wall and the bottom wall. The insulative cavity may be configured to reduce heat transfer through the lid. A lip may be formed around at least a portion of an outer surface of the side wall or the top wall. The lid may be configured to be slidably received in the opening of the temperature-conserving container such that at least a portion of the lip engages the top rim and forming a seal between the outer surface of the side wall and the inner surface of the opening, thereby sealing the temperature-conserving container. 
     In non-limiting examples disclosed herein, a temperature-conserving bowl system may include a bowl comprising an opening defining an inner surface of the opening and a top rim and a lid configured to be removably received within the opening of the bowl. The lid may include a bottom wall, a side wall formed around a perimeter of the bottom wall, a top wall connected to the side wall, and an insulative cavity between the top wall and the bottom wall. The insulative cavity may be configured to reduce heat transfer through the lid. A lip may be formed around at least a portion of an outer surface of the side wall or the top wall. The lid may be configured to be slidably received in the opening of the bowl such that at least a portion of the lip engages the top rim, and an outer surface of the side wall forms a seal against the inner surface of the opening of the bowl. 
     In non-limiting examples disclosed herein, a temperature-conserving bowl system may include a bowl comprising an opening and a lid configured to be removably received within the opening of the bowl. The lid may include a unitary bottom portion comprising a bottom wall, a top portion comprising a top wall spaced vertically apart from the bottom wall, and a side wall formed around a perimeter of the top wall and a perimeter of the bottom wall and extending between the top wall and bottom wall. At least a portion of the side wall may be part of the unitary bottom portion. An insulative cavity may be between the top wall and the bottom wall, and the insulative cavity may be configured to reduce heat transfer through the lid. An outer surface of the side wall may form a seal against an inner surface of the opening of the bowl. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present description will be understood more fully when viewed in conjunction with the accompanying drawings of various examples of temperature-conserving containers. The description is not meant to limit the temperature-conserving containers to the specific examples. Rather, the specific examples depicted and described are provided for explanation and understanding of temperature-conserving containers. Throughout the description the drawings may be referred to as drawings, figures, and/or FIGS. 
         FIG.  1    illustrates a temperature-conserving container embodied as a pitcher, according to an embodiment. 
         FIG.  2    illustrates an exploded view of the pitcher, according to an embodiment. 
         FIG.  3    illustrates a slider of a lid of the pitcher, according to an embodiment. 
         FIG.  4    illustrates a further temperature-conserving container embodied as a bowl, according to an embodiment. 
         FIG.  5    illustrates a cross-sectional view of the bowl, according to an embodiment. 
         FIG.  6    illustrates a detail view of a gasketed joint of the bowl, according to an embodiment. 
         FIG.  7    illustrates a method of making a temperature-conserving container, according to an embodiment. 
         FIG.  8 A  illustrates a lid, according to an embodiment. 
         FIG.  8 B  illustrates a cutaway view of a lid, according to an embodiment. 
         FIG.  8 C  illustrates a cross-section view of a lid, according to an embodiment. 
         FIG.  8 D  illustrates a cross-section detail view of an edge of a lid, according to an embodiment. 
         FIG.  9 A  is a perspective view of a lid, according to an embodiment. 
         FIG.  9 B  is a cross-section view of the lid of  FIG.  9 A . 
         FIG.  9 C  is an exploded view of the lid of  FIG.  9 B . 
         FIG.  10    is a perspective view of a bowl with the lid of  FIG.  9 C . 
         FIG.  11    is a cross-sectional view of the bowl and lid of  FIG.  10   . 
     
    
    
     DETAILED DESCRIPTION 
     Temperature-conserving containers as disclosed herein will become better understood through a review of the following detailed description in conjunction with the figures. The detailed description and figures provide merely examples of the various embodiments of temperature-conserving containers. Many variations are contemplated for different applications and design considerations; however, for the sake of brevity and clarity, all the contemplated variations may not be individually described in the following detailed description. Those skilled in the art will understand how the disclosed examples may be varied, modified, and altered and not depart in substance from the scope of the examples described herein. 
     Conventional containers may include vacuum-insulated vessels configured to hold a fluid or other item and reduce heat loss to the environment. Examples may include powder-coated double-walled stainless steel drink containers. Such containers may provide for insulation of their contents to reduce convective and conductive heat losses. 
     During research and development in the field of kitchen serving instruments, the present inventor has determined that conventional vacuum-insulated drink vessels may be of limited capacity both in quantity and type and further may do little to minimize radiative heat loss via radiation. Among others, radiative heat loss presents issues for larger containers such as bowls having a large opening area, which is not vacuum-insulated. Further, the lids of large-opening containers such as bowls present difficulties in providing for a double-walled vacuum lid, as attempting to evacuate large volumes (e.g., the space between the walls of a double-walled bowl lid) may deform the product (e.g., a double-walled vacuum lid). For example, the lid walls enclosing a large volume may bend as they are sucked inward under the vacuum pressure as the lid is removed from the bowl. Such deformities may further induce sealing problems-the lid’s shape may deform and not fit the sides of the bowl sufficiently. These and other issues may cause food, drink, or other contents to be not kept at or near their desired temperature for the desired period of time. 
     Implementations of temperature-conserving containers may address some or all of the problems described above. Temperature-conserving containers may include vessels for food transportation and serving, which may include a reservoir and a lid. The reservoir may include a sidewall, a bottom wall, and an opening. The lid may be configured to be insertably disposed at least partially within the opening. The lid may include a reflector and a gasket channel, the gasket channel having a gasket disposed at least partially therein. The reflector may include copper or another material having a significant ability to reflect heat radiation (e.g., silver). 
     Embodiments of temperature-conserving containers may optimize aspects of conduction, convection, and radiation to keep food closer to its intended temperature and for ease of transport. Further, such embodiments may provide for a reduction in radiative heat losses for both large- and small-opening containers by implementing a reflector to reflect heat radiating from the substance for which temperature control is sought. 
       FIG.  1    illustrates a temperature-conserving container system embodied as a pitcher  100 , according to an embodiment. The pitcher  100  may be configured to maintain, for example, a liquid or food item near a desired temperature, which is hotter or colder than a temperature of the surrounding environment. 
     The pitcher  100  may include a reservoir  101  and a lid  102 . The reservoir may have a form of a cylindrical container having a bottom wall  106  and a handle  107 . The handle  107  may be used for carrying the pitcher  100  or maneuvering it to pour contents. 
     The reservoir  101  may have an opening  108  near a top of the reservoir configured such that the lid  102  may be disposed therein. The lid  102  may be configured to fit into the top opening of the pitcher  100 . The lid  102  may be configured with an opening  111 . This opening  111  may selectively blocked by a slider  104 . In this way, the slider  104  may prevent substance within the pitcher  100  from exiting the pitcher  100  when in a “closed” position (i.e., blocking the flow of a substance from the opening of the lid). 
     The reservoir  101 , the lid  102 , and/or the slider  104  may be constructed of a metal (e.g., stainless steel) or a plastic (e.g., ABS, polylactic acid (PLA), polycarbonate (PG), polyethylene terephthalate (PET, PETT, PETG, PETE), nylon, high density polyethylene (HDPE), polyvinyl chloride (PVC), low density polyethylene (LDPE), polypropylene (PP), or polystyrene, or other suitable plastics). The plastic may be considered a BPA-free plastic (e.g., TRITAN™). 
     The reservoir  101  and/or the lid  102  may be of a double-walled construction, that is, having an insulative cavity. Such cavities may be evacuated of air sufficient to reduce heat loss through conduction via the walls to the environment. (i.e., the walls may be vacuum-insulated). 
       FIG.  2    illustrates an exploded view of the pitcher  100 , according to an embodiment. The exploded view of the pitcher  100  may provide detail as to the fit of the lid  102  into the top opening  108  of the reservoir  101 . The exploded view of the pitcher  100  may provide detail as to the fit of the slider  104  to the lid  102 . 
     The slider  104  may be configured to be disposed within a channel  110  formed in a cap  103  of the lid  102 . By sliding the slider  104  within the channel  110 , the slider  104  may selectively block an opening  111  of the cap  103 , thereby permitting or restricting flow of a substance into or out of the pitcher  100 . 
     The lid  102  may be configured to fit into an opening  108  of a reservoir  101  to compose the pitcher  100 . The opening  108  of the reservoir  101  defines an inner surface  112  of the opening  108  and may be of a similar profile to a portion of the lid  102 . For example, the profile of the opening  108  may be slightly larger than the profile of the portion of the lid  102  so as to permit insertion of the portion of the lid  102  into the opening  108 . 
     The lid  102  may have a bottom side  109 . The bottom side  109  may be the face of the lid  102 , which when the pitcher  100  is assembled and in use, faces a substance contained within the pitcher  100 . The bottom side  109  may have a reflector disposed thereon. The reflector may include a reflective material, for example copper or silver. Some embodiments, however, may omit the reflector. 
     The reflective material may have properties conducive to reflecting heat back toward the contents of the temperature-conserving container. The reflective material may have a high reflectance and low emissivity at temperatures near or below 100° C. Having a reflector that includes the reflective material disposed on or within the lid  102  may improve the ability of the pitcher  100  to contain heat, thus keeping the contents of the pitcher  100  closer to their desired temperature. In some embodiments, copper or silver may be used as a reflective material. Copper or silver, each having a high reflectance, provide for efficient reflecting of infrared radiation emitted from the contents of the pitcher  100 , back to the contents of the pitcher  100 . 
     The reflector may include a sheet of the reflective material, may be another material having the reflective material disposed thereon, or the reflective material may be disposed directly on the bottom side  109  (e.g., using deposition or electrolysis). In embodiments where the reflective material is not disposed directly on the bottom side  109 , the reflector may be fitted or adhered to the bottom side  109  of the lid  102 , or another portion of the lid  102 . Further, in some embodiments, the reflector may be disposed within the cap  103  of the lid  102 . In some embodiments, the reflector may be an oxidized metal to reduce reactivity. 
     The lid  102  may have a gasket disposed thereon, which may be configured to form a seal. The gasket may be, for example, silicone, rubber, EPDM, nitrile, or another suitable gasketing and/or food-grade material. The gasket may be, for example, a ring gasket. 
       FIG.  3    illustrates the slider  104  of the lid  102  of the pitcher  100 , according to an embodiment. The slider  104  may provide an ability to open and close a spout of the pitcher for example, for pouring out of a liquid contained therein. 
     The slider  104  may have a gasket  105  disposed thereon to assist in forming a seal with the cap  103  of the lid  102 . The gasket  105  may be, for example, silicone, rubber, EPDM, nitrile, or another suitable gasketing and/or food-grade material. 
       FIG.  4    illustrates a further temperature-conserving container embodied as a bowl  200 , according to an embodiment. The bowl  200  may be configured to maintain, for example, a liquid or food item near a desired temperature hotter or colder than that of the surrounding environment. 
     In various embodiments, the bowl  200  may be used to store food items including, inter alia, salads, cakes, casseroles, soups, ice cream, cold desserts, and other hot or cold foods. Due to the food item’s geometry or the way in which it must be accessed, such food items may be optimally stored and accessed from within a bowl-like container such as bowl  200 , even though they are not optimally stored within a traditional double-walled vacuum-insulated drink vessel. 
     The bowl  200  may include a reservoir  201  and a lid  202 . The reservoir  201  may have a form of a bowl, such as a large serving bowl. The reservoir  201  may have an opening  208  near a top of the reservoir configured such that the lid  202  may be disposed therein. The lid  202  may be configured to fit into the top opening  208  of the bowl  200 . The lid  202  may be configured to prevent substance within the bowl  200  from exiting the bowl  200  when in a “closed” position (i.e., blocking the flow of or access to a substance from the opening of the lid). 
     The reservoir  201  and/or the lid  202  may be constructed of a metal (e.g., stainless steel) or a plastic (e.g., ABS, polylactic acid (PLA), polycarbonate (PG), polyethylene terephthalate (PET, PETT, PETG, PETE), nylon, high density polyethylene (HDPE), polyvinyl chloride (PVC), low density polyethylene (LDPE), polypropylene (PP), or polystyrene, or other suitable plastics). The plastic may be considered a BPA-free plastic (e.g., TRITAN™). 
     The reservoir  201  and/or the lid  202  may be of a double-walled construction, that is, having an insulative cavity. Such cavities may be evacuated of air sufficient to reduce heat loss through conduction via the walls to the environment (i.e., the walls may be vacuum-insulated). 
       FIG.  5    illustrates a cross-sectional view of the bowl  200 , according to an embodiment. The cross-sectional view of the bowl  200  may provide detail as to the fit of the lid  202  into the top opening  208  of the reservoir  201 . The lid  202  may be configured to fit into an opening of a reservoir  201  to compose the bowl  200 . The opening  208  of the reservoir  201  may be of a similar profile to a portion of the lid  202 . For example, the profile of the opening  208  may be slightly larger than the profile of the lid  202  so as to permit insertion of the portion of the lid  202  into the opening  208 . The lid  202  may have a bottom side  204 . The bottom side  204  may be the face of the lid  202 , which when the bowl  200  is assembled and in use, faces a substance contained within the bowl  200 . The bottom side  204  may have a reflector disposed thereon. The reflector may include a reflective material, for example copper or silver. 
     The reflective material may have properties conducive to reflecting heat back toward the contents of the temperature-conserving container. The reflective material may have a high reflectance and low emissivity at temperatures near or below 100° C. Having a reflector that includes the reflective material disposed on or within the lid  202  may improve the ability of the bowl  200  to contain heat, this keeping the contents of the bowl  200  closer to their desired temperature. In some embodiments, copper or silver may be used as a reflective material. Copper or silver, each having a high reflectance, provide for efficient reflecting of infrared radiation emitted from the contents of the bowl  200 , back to the contents of the bowl  200 . 
     The reflector may include a sheet of the reflective material, may be another material having the reflective material disposed thereon, or the reflective material may be disposed directly on the bottom side  204  (e.g., using deposition or electrolysis). In embodiments where the reflective material is not disposed directly on the bottom side  204 , the reflector may be fitted or adhered to the bottom side of the lid  202 , or another portion of the lid  202 . Further, in some embodiments, the reflector may be disposed within the lid  202 . In some embodiments, the reflector may be an oxidized metal to reduce reactivity. 
       FIG.  6    illustrates a detail view of a gasketed joint of the bowl  200 , according to an embodiment. The gasketed joint may provide for a seal to prevent the escape of, for example, steam from the bowl  200  or entrance of air from the environment into the bowl  200 . 
     The lid  202  may have a gasket  203  disposed thereon, which may be configured to form a seal between the lid  202  and the reservoir  201 . The gasket  203  may be, for example, silicone, rubber, EPDM, nitrile, or another suitable gasketing and/or food-grade material. The gasket  203  may be, for example, a ring gasket. 
       FIG.  7    illustrates a method  300  of making a temperature-conserving container, according to an embodiment. The method  300  may provide for making a temperature-conserving container configured to maintain, for example, a liquid near a desired temperature hotter or colder than that of the surrounding environment. 
     At  302 , a reservoir and a lid may be provided. The reservoir may include a sidewall, a bottom wall, and an opening. The lid may be configured to be insertably disposed at least partially within the opening. At  304 , a reflector may be disposed on the lid. The lid may include a reflector and a gasket channel, the gasket channel having a gasket disposed at least partially therein. The reflector may include copper or another material having a significant ability to reflect heat radiation (e.g., silver). 
       FIGS.  8 A- 8 D  illustrates a lid  400  for a temperature-conserving container, according to an embodiment. The lid  400  may be used to contain (e.g., enclose, seal, cover) contents within a temperature-conserving container and may further assist in keeping the contents at a desired temperature. The lid  400  may have a lift tab  401 , which may enable a user to open or remove the lid  400  from the temperature-conserving container to access the contents or vent the temperature-conserving container. 
       FIG.  8 B  illustrates a cutaway view of the lid  400 , according to an embodiment. The lid  400  may have a top portion  402  including a top wall  410  and a bottom portion  403  including a bottom wall  412 . At least one of the top portion  402  and the bottom portion  403  may have one or more ribs  404 ,  405 . The ribs  404 ,  405  may provide for enforcing separation between the top portion  402  and the bottom portion  403 . For example, the ribs  404 ,  405  may increase the rigidity of the top wall  410  and/or the bottom wall  412  to prevent the top and/or bottom wall(s)  410 ,  412  from deforming during the manufacturing process. A side wall  414  (see  FIG.  8 D ) and the ribs  404 ,  405  may at least partially define an insulative cavity  416  between the top portion  402  and the bottom portion  403 . The insulative cavity  416  may be a vacuum gap (e.g., a partial vacuum gap) or an air gap, and in this way the insulative cavity  416  may provide for an insulative cavity to reduce heat escape via the lid  400 . In embodiments where the insulative cavity is configured as a vacuum gap, the ribs  404 ,  405  prevent the top portion  402  and/or the bottom portion  403  from deflecting toward each other as the air is evacuated from the insulative cavity  416 . 
       FIG.  8 C  illustrates a cross-section view of the lid  400 , according to an embodiment. The ribs  404 ,  405  of the top portion  402  and the bottom portion  403 , respectively, may be, for example, substantially concentric as illustrated in  FIG.  8 C . ribs  404 . Such example concentric ribs  404  and  405  may provide for the structural integrity of the lid  400 , thereby preventing the lid  400  from deforming during the manufacturing process and enforcing separation between the top portion  402  and the bottom portion  403 . In the illustrated embodiments, the ribs  404 ,  405  only extend a portion of the way between the top wall  410  and the bottom wall  412  so that there is space between the top or bottom surface of the ribs  404 ,  405  and the top and bottom walls  410 ,  412 . This may be useful, for example, to prevent the lid  400  from deforming while providing an insulative gap  416  between the opposing walls  410 ,  412 . Some embodiments, however, may include at least one rib that extends between the top wall  410  and the bottom wall  412 . 
       FIG.  8 D  illustrates a cross-section detail view of an edge of the lid  400 , according to an embodiment. The edge may provide for a sealing fit of the lid  400  into an opening of a temperature-conserving container. The edge of the lid  400  may include a side wall  414  that extends downward from an upper lip  406  around the perimeter of the lid  400 . The upper lip  408  may be configured to engage a rim of the opening of the temperature-conserving container to prevent over insertion of the lid  400 . The side wall  414  includes a channel  407  and a lower lip  408  forming a lower edge of the channel  407 . The channel  407  is configured to receive a gasket that forms a seal between an outer surface  422  of the side wall  414  and a side of the temperature-conserving container proximate the opening thereof. 
     In some embodiments, at least a portion of the side wall  414  may be integrally formed with the top wall  410  and/or at least a portion of the side wall  414  may be integrally formed with the bottom wall  412 . For example, the top portion  402  may be a unitary top portion and/or the bottom portion  403  may be a unitary bottom portion. The top portion  402  and the bottom portion  403  are coupled together and a joint  418 . The joint may be at various locations in or on the side wall  414 . In the example shown in  FIG.  8 D , the joint  418  is located in the side wall  414 . The side wall  414  includes an upper portion  424  that is integrally formed with and extending downward from the top wall  410  and a lower portion  426  that is integrally formed with and extending downward from the bottom wall  412 . The joint  418  is located in the side wall  414  between the upper surface  428  of the bottom wall  412  and a lower edge of the upper portion  424  of the side wall  414 . Other embodiments, however, may have a differently configured joint between the top portion  402  and the bottom portion  403 . 
     In some embodiments, the lid  400  may include a reflector. The reflector may include a sheet of the reflective material, may be another material having the reflective material disposed thereon, or the reflective material may be disposed directly on the lid (e.g., using deposition or electrolysis). In embodiments where the reflective material is not disposed directly on the lid, the reflector may be fitted or adhered to the lid. Further, in some embodiments, the reflector may be disposed within the lid. In some embodiments, the method  300  may further comprise oxidizing the reflector to reduce reactivity. 
       FIGS.  9 A- 9 C  illustrate another embodiment of a lid  500  for a temperature-conserving container  600 , for example a bowl (see  FIGS.  10 - 11   ). The lid  500  may be configured to contain (e.g., enclose, seal, cover) contents within the temperature-conserving container and may further assist in keeping the contents at a desired temperature. The lid  500  may include a top wall  502 , a bottom wall  504 , and a side wall  506  which extends vertically between the top wall  502  and the bottom wall  504 . The side wall  506  may extend around the perimeters of the top wall  502  and the bottom wall and encloses an insulative cavity  508  between the top wall  502  and the bottom wall  504 , which is configured to reduce heat transfer through the lid  500 . The lid  500  is configured to be slidably received in an opening  602  of the temperature-conserving container  600  and forms a seal between the outer surface  326  of the side wall  506  and the inner surface  604  of the opening  602 , thereby sealing the temperature-conserving container  600 . 
     Referring to  FIGS.  9 B and  9 C , the top wall  502  is generally planar and includes an upper surface  510  and an opposite lower surface  512 . At least one rib  514  may be formed on the lower surface  512  of the top wall  502 . This may be useful, for example, in order to increase the rigidity of the top wall  502  to prevent the top wall  502  from flexing due to temperature related pressure changes in the insulative cavity  508 , and/or to space the top wall  502  apart from the bottom wall  504 . The bottom wall  504  is generally planar an includes an upper surface  516  and an opposite lower surface  518 . The side wall  506  is formed around the perimeter of the bottom wall  504  and extends upwards from the upper surface  516  of the bottom wall  504  to the lower surface  512  of the top wall  502 , defining the sealed insulative cavity  508  therebetween. To form a seal between the side wall  506  and the temperature-conserving container  600 , the side wall  506  may include a gasket  522 . In the illustrated examples, the side wall  506  includes a gasket  522  received in a channel  524  formed in and around the outer surface  526  of the side wall  506 . Some embodiments, however, may be configured with a lid that seals against the temperature-conserving container without a gasket, or the gasket may be located elsewhere such as to provide a seal between the lip  528  and the top rim of the bowl opening  602  as described below. 
     In some embodiments, a lip  528  may be formed around at least a portion of an outer surface  526  of the side wall  506  or the top wall  502  and may be configured to prevent the lid  500  from moving entirely into the opening  602  of the temperature-conserving container  600 . In the illustrated embodiments, for example, the lid  500  includes a lip  528  configured as an annular lip that is formed around the outer surface  526  of the side wall  506  and the top wall  502 . The lip  528  is configured to engage a top rim  606  of the opening  602  to prevent over insertion of the lid  500  into the temperature-conserving container  600 . Additionally or alternatively, the lid may include a lift tab  530  configured to be grasped by a user to remove the lid  500  from the temperature-conserving container  600 . The illustrated lift tab  530  projects outward from the side wall  506  and is an integrally formed part of the unitary bottom portion  552 . This may be useful, for example, so that the lid  500  may be lifted from the temperature-conserving container  600  without separating the top wall  502  from the bottom wall  504  due to temperature related pressure changes in the insulative cavity  508 . 
     In the illustrated embodiments, the upper surface of the lid  500  is generally flat and planar. The lift tab  530  has an upper surface  532  that is generally flush (i.e., coplanar) with the upper surface  510  of the top wall  502  and an upper surface  534  of the lip  528 . This may be useful, for example, in order to provide an aesthetically pleasing appearance of the lid  500  and the temperature-conserving container  600 . Some embodiments, however, may include at least one feature which extends upwards from the lid. Additionally or alternatively, a lid may be configured with a lip, lift tab, and/or top wall having an upper surface that is not flush with each other. 
     In some embodiments, the lid  500  may include a unitary top portion  550  and a unitary bottom portion  552  that are coupled together at a joint  554  to form the lid  500  and seal the insulative cavity  508 . For example, at least one of the top portion  550  and the bottom portion  552  may be configured as a unitary component that is formed as one continuous piece, such as a single molded piece. Some embodiments, however, may include a unitary top portion and/or a unitary top portion that includes multiple pieces which are rigidly coupled to each other, such as a single part formed from multiple pieces that are welded together. In the illustrated embodiments, the lid  500  is formed by a unitary top portion  550  including the top wall  502  and a unitary bottom portion  552  including the bottom wall  504  and at least a portion of the side wall  506 , which is integrally formed with the bottom wall  504 . 
     The unitary bottom portion  552  may include at least a portion of the lip  528  and/or at least a portion of the lift tab  530 . The inventor has recognized that providing a unitary bottom portion  552  comprising at least part of the lift tab  530  provides strength and integrity to withstand pressure changes that occur within the sealed cavity  508  of the temperature conserving container. Where the cavity  508  is large and a decrease in temperature has occurred, for example, a vacuum may develop where the pressure inside the cavity  508  is lower and a significant force may be imparted on the lid  500  to pull it off. The unitary construction described herein provides an improved lid that does not break or separate when such forces are exerted on it, and the inventor has recognized that it is particularly important for bowls having a substantially size cavity, such as the bowls described herein that are 10 inches in diameter or larger. Additionally or alternatively, at least a portion of the lip  528  and/or at least a portion of the lift tab  530  may be part of the unitary top portion  550 . Further still, some embodiments may include a lip  528  and/or a lift tab  530  that is separate from the unitary top portion  550  and the unitary bottom portion  552 . 
     As illustrated in  FIG.  9 B , the joint  554  between the unitary top portion  550  and the unitary bottom portion  552  is located between the top wall  502  and the side wall  506 . The joint  554  may include a recessed lip  556  formed in the unitary bottom portion  552  proximate the top of the side wall  506  and configured to receive the top portion  550 . In the illustrated embodiments, the recessed lip  556  is formed on a top rim  507  of the side wall  506  and extends around the insulative cavity  508 . An outer wall  558  of the recessed lip  556  may be formed by the lip  528  and/or the lift tab  530 . 
     To form a seal between the unitary top portion  550  and the unitary bottom portion  552 , the unitary top portion  550  (i.e., the top wall  502 ) is seated on the recessed lip  556 . A gasket  562  may be positioned between the recessed lip  556  and the unitary top portion  550  and is configured to form a seal therebetween, thereby sealing the insulative cavity  508 . For example, the unitary top portion  550  may include a groove  560  formed around the perimeter of the top wall  502 . A gasket  562  is received in the groove  560  and is configured to form a seal between the top wall  502  and the outer wall  558  of the recessed lip  556 . In the illustrated embodiments, the unitary top portion  550  is coupled to the unitary bottom portion  552  by a press-fit (i.e., friction fit) connection utilizing the gasket  562 . Other embodiments, however, may use a different type of connection between the unitary top portion  550  and the unitary bottom portion  552 , such as via other mechanical fastening processes, welding (e.g., ultrasonic welding), or utilizing adhesives. 
     Some embodiments may include positioning features configured to position the top wall  502  relative to the bottom wall  504  and/or side wall  506  when coupling the unitary top portion  550  relative to the unitary bottom portion  552 . For example, as illustrated in  FIG.  9 C , the unitary top portion  550  includes top positioning members  570  formed on the lower surface  512  of the top wall  502  and the unitary bottom portion  552  includes corresponding bottom positioning members  572  formed on the upper surface  516  of the bottom wall  504 . The top positioning members  570  are configured to engage with the bottom positioning features  572  to require that the unitary top portion  550  connect to the unitary bottom portion  552  in a desired orientation. In the illustrated embodiments, the top positioning members  570  are each configured to be received in a slot  574  formed between the semi-circular bottom positioning features  572 , thereby locking the orientation of the top wall relative to the bottom wall  504  and the side wall  506 . However, some embodiments may include a unitary top portion and/or a unitary bottom portion with at least one positioning member or feature that is different than those of the illustrated embodiments. 
     Referring to  FIGS.  10  and  11   , an embodiment of a temperature-conserving bowl system  650  may include a lid, such as the lid  500  of  FIGS.  9 A- 9 C , and a bowl  600  including an opening  602  that defines an inner surface  604  and a top rim  606  of the opening  602 . In the illustrated embodiments, the bowl  600  is an insulated double-walled bowl with an inner wall  610 , an outer wall  612 , and an insulative gap  614  between the inner and outer walls  610 ,  612 . Some embodiments, however, may include a different type of bowl or a different type of temperature-conserving container. 
     The lid  500  is configured to be slidably received in the opening  602  of the bowl  600  such that at least a portion of the lip  528  engages the top rim  606  of the bowl  600  and an outer surface  526  of the side wall  506  forms a seal against the inner surface  604  of the opening  602  of the bowl  600 . The shape and size of the outer profile of the portion of the lid  500  received in the opening  602  corresponds to the shape and size of inner surface  604  of the opening  602  such that an airtight seal is formed between the outer surface  526  of the side wall  506  and the inner surface  604  of the opening  602 . 
     For example, an embodiment of the bowl  600  may have an outer diameter  652  of about 10 inches and a depth  656  of about 4 inches, and the opening  602  of the bowl  600  may have a diameter  654  of about 9.6 inches, depending on the thickness of the double-walled bowl. In such an embodiment, the lid  500  configured for use with the bowl  600  may have an overall diameter  668  of about 10 inches, and the diameter  658  of the insertable portion of the lid  500  (i.e., the diameter of the side wall  506 ) of about 9.5 inches to provide clearance for the seal-forming gasket  522  between the side wall  506  and the inner surface  604  of the opening  602 . The lid  500  for the bowl that is 10 inches may have a thickness  662  of about 0.6 inches, with an insertable portion having a thickness  664  of about 0.5 inches. The lift tab  530  may extend a distance  660  of about 1 inch past the lip  528  so that it may be grasped by a user. The lid  500  may be scaled accordingly to fit a smaller or lager bowl depending on the diameter of the opening  602 . 
     Other embodiments, however, may have a lid  500  and/or a bowl with at least one different dimension. For example, a bowl may have an outer diameter  652  that is between about 6 inches and about 16 inches and/or a depth  656  between about 1 inch and about 6 inches. The size of the opening  602  may vary based on the size of the bowl  600  and may have a diameter  654  that is between about 7.6 inches and about 15.6 inches. The lid  500  may have an overall diameter  668  between about 8 inches and about 16 inches, and the diameter  658  of the insertable portion of the lid  500  (i.e., the diameter of the side wall  506 ) may be between about 7.5 inches and about 15.5 inches. The lid  500  may have a thickness  662  that is between about 0.25 inches and about 1.5 inches, with an insertable portion having a thickness  664  of about 0.125 inches to about 1.375 inches. Additionally or alternatively, the lift tab  530  may extend a distance  660  of about 0.5 inches to about 2 inches past the lip  528 . Further still, some embodiments may have at least one dimension that is different than those of the illustrated embodiments. 
     The temperature-conserving container  600  and/or the lid  500  may include at least one part that is formed of a metal (e.g., stainless steel) or a plastic (e.g., ABS, polylactic acid (PLA), polycarbonate (PG), polyethylene terephthalate (PET, PETT, PETG, PETE), nylon, high density polyethylene (HDPE), polyvinyl chloride (PVC), low density polyethylene (LDPE), polypropylene (PP), and/or polystyrene, or other suitable plastics). The plastic may be considered a BPA-free plastic (e.g., TRITAN™). For example, the bowl  600  may be at least partially formed of metal and at least one of the top wall  502 , the bottom wall  504 , the side walls  506 , the lip  528 , and the lift tab  530  may be formed of a hard plastic (e.g., TRITAN™). Some embodiments, however, may include a lid and/or a bowl that is at least partially formed from a different material. 
     A feature illustrated in one of the figures may be the same as or similar to a feature illustrated in another of the figures. Similarly, a feature described in connection with one of the figures may be the same as or similar to a feature described in connection with another of the figures. The same or similar features may be noted by the same or similar reference characters unless expressly described otherwise. Additionally, the description of a particular figure may refer to a feature not shown in the particular figure. The feature may be illustrated in and/or further described in connection with another figure. 
     Elements of processes (i.e., methods) described herein may be executed in one or more ways such as by a human, by a processing device, by mechanisms operating automatically or under human control, and so forth. Additionally, although various elements of a process may be depicted in the figures in a particular order, the elements of the process may be performed in one or more different orders without departing from the substance and spirit of the disclosure herein. 
     The foregoing description sets forth numerous specific details such as examples of specific systems, components, methods and so forth, in order to provide a good understanding of several implementations. It will be apparent to one skilled in the art, however, that at least some implementations may be practiced without these specific details. In other instances, well-known components or methods are not described in detail or are presented in simple block diagram format in order to avoid unnecessarily obscuring the present implementations. Thus, the specific details set forth above are merely exemplary. Particular implementations may vary from these exemplary details and still be contemplated to be within the scope of the present implementations. 
     Related elements in the examples and/or embodiments described herein may be identical, similar, or dissimilar in different examples. For the sake of brevity and clarity, related elements may not be redundantly explained. Instead, the use of a same, similar, and/or related element names and/or reference characters may cue the reader that an element with a given name and/or associated reference character may be similar to another related element with the same, similar, and/or related element name and/or reference character in an example explained elsewhere herein. Elements specific to a given example may be described regarding that particular example. A person having ordinary skill in the art will understand that a given element need not be the same and/or similar to the specific portrayal of a related element in any given figure or example in order to share features of the related element. 
     It is to be understood that the foregoing description is intended to be illustrative and not restrictive. Many other implementations will be apparent to those of skill in the art upon reading and understanding the above description. The scope of the present implementations should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. 
     The foregoing disclosure encompasses multiple distinct examples with independent utility. While these examples have been disclosed in a particular form, the specific examples disclosed and illustrated above are not to be considered in a limiting sense as numerous variations are possible. The subject matter disclosed herein includes novel and non-obvious combinations and sub-combinations of the various elements, features, functions and/or properties disclosed above both explicitly and inherently. Where the disclosure or subsequently filed claims recite “a” element, “a first” element, or any such equivalent term, the disclosure or claims is to be understood to incorporate one or more such elements, neither requiring nor excluding two or more of such elements. 
     As used herein “same” means sharing all features and “similar” means sharing a substantial number of features or sharing materially important features even if a substantial number of features are not shared. As used herein “may” should be interpreted in a permissive sense and should not be interpreted in an indefinite sense. Additionally, use of “is” regarding examples, elements, and/or features should be interpreted to be definite only regarding a specific example and should not be interpreted as definite regarding every example. Furthermore, references to “the disclosure” and/or “this disclosure” refer to the entirety of the writings of this document and the entirety of the accompanying illustrations, which extends to all the writings of each subsection of this document, including the Title, Background, Brief description of the Drawings, Detailed Description, Claims, Abstract, and any other document and/or resource incorporated herein by reference. 
     As used herein regarding a list, “and” forms a group inclusive of all the listed elements. For example, an example described as including A, B, C, and D is an example that includes A, includes B, includes C, and also includes D. As used herein regarding a list, “or” forms a list of elements, any of which may be included. For example, an example described as including A, B, C, or D is an example that includes any of the elements A, B, C, and D. Unless otherwise stated, an example including a list of alternatively-inclusive elements does not preclude other examples that include various combinations of some or all of the alternatively-inclusive elements. An example described using a list of alternatively-inclusive elements includes at least one element of the listed elements. However, an example described using a list of alternatively-inclusive elements does not preclude another example that includes all of the listed elements. And, an example described using a list of alternatively-inclusive elements does not preclude another example that includes a combination of some of the listed elements. As used herein regarding a list, “and/or” forms a list of elements inclusive alone or in any combination. For example, an example described as including A, B, C, and/or D is an example that may include: A alone; A and B; A, B and C; A, B, C, and D; and so forth. The bounds of an “and/or” list are defined by the complete set of combinations and permutations for the list. 
     Where multiples of a particular element are shown in a FIG., and where it is clear that the element is duplicated throughout the FIG., only one label may be provided for the element, despite multiple instances of the element being present in the FIG. Accordingly, other instances in the FIG. of the element having identical or similar structure and/or function may not have been redundantly labeled. A person having ordinary skill in the art will recognize based on the disclosure herein redundant and/or duplicated elements of the same FIG. Despite this, redundant labeling may be included where helpful in clarifying the structure of the depicted examples. 
     The Applicant(s) reserves the right to submit claims directed to combinations and sub-combinations of the disclosed examples that are believed to be novel and non-obvious. Examples embodied in other combinations and sub-combinations of features, functions, elements and/or properties may be claimed through amendment of those claims or presentation of new claims in the present application or in a related application. Such amended or new claims, whether they are directed to the same example or a different example and whether they are different, broader, narrower or equal in scope to the original claims, are to be considered within the subject matter of the examples described herein.