All-Glass Travel Mug

Abstract

A beverage container for hot or cold beverages, where the lid and base are connected via a glass joint. The glass joint forms a seal between the lid and base and eliminates the need for a synthetic material to form such a seal. The base has a double wall construction forming a cavity between the two walls. One or more of the surfaces facing the cavity are coated with a thermally reflective coating, which along with the glass materials, reduces heat transfer to the external surroundings. The lid is formed by a glass shell with an internal cavity, where the internal surfaces defining the cavity are optionally coated with a thermally reflective coating to further insulate the beverage container. A vent hole may be formed in a bottom of a dual-walled beverage container to prevent the formation of a vacuum. The outer surface of an inner wall of a dual-walled beverage container may have an inductively couplable layer secured to the inner wall to permit heating of fluids.

Claims

1. A beverage container or kettle comprising: a body having a closed bottom end, an open upper end, and constructed from glass, wherein the body is formed with a double wall having an inner wall and an outer wall, wherein a wall gap is defined by an inner surface of the outer wall and an outer surface of the inner wall, wherein the closed bottom end is formed with an inner bottom wall and an outer bottom wall to form a double bottom wall with the inner bottom wall continuous with the inner wall and the outer bottom wall continuous with the outer wall, wherein a bottom gap defined by an inner surface of the outer bottom wall and an outer surface of the inner bottom wall is continuous with the wall gap, wherein a vent hole is formed or created in the outer bottom wall in fluid communication with the wall gap, and wherein an inner face of the inner wall proximal the upper end is formed from ground glass to form a first half of a discontinuous or interrupted glass joint; and, a lid constructed from glass having a top lid surface and a bottom lid surface spaced by a lid side face, wherein the lid has portions defining a drinking port or side channel that extends from the top lid surface down to the bottom lid surface and partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face and other portions that define a vent port or vent channel that extends from the top lid surface down to the bottom lid surface partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face, wherein the lid side face is formed from ground glass to form a second half of the discontinuous or interrupted glass joint, wherein the lid side face mates with, and registers against, the inner face of the at least one wall, except at the locations of the drinking port and the vent port, to form the discontinuous or interrupted glass joint when the lid is inserted into the upper open end of the body.

2. The beverage container or kettle of claim 1 further comprising a body wall closure secured in the vent hole.

3. The beverage container or kettle of claim 1 wherein the lid has a cavity defined by the upper lid surface, the lower lid surface and the lid side wall.

4. The beverage container or kettle of claim 3 wherein the inner surface of the at least one wall proximal the upper open end is frustoconical in shape, and wherein the lid side wall is frustoconical in shape to mate with the inner surface of the at least one wall proximal the upper open end.

5. The beverage container or kettle of claim 3 wherein at least one surface of the walls defining the cavity is coated with infrared-reflecting coating.

6. The beverage container or kettle of claim 3 wherein the cavity is filled with an insulating gas, wherein the insulating gas is selected from the group consisting of air, low-oxygen gas, low-pressure gas, low-conductivity gas and mixtures thereof.

7. The beverage container or kettle of claim 1 wherein at least one surface of the inner surface of the outer wall and the outer surface of the inner wall is at least partially coated with an infrared-reflecting coating.

8. The beverage container or kettle of claim 7 wherein the infrared reflective coating is coated onto the at least one surface in an artistic pattern.

9. The beverage container or kettle of claim 1 wherein the wall gap is filled with an insulating gas, wherein the insulating gas is selected from the group consisting of air, low-oxygen gas, low-pressure gas, low-conductivity gas and mixtures thereof.

10. The beverage container or kettle of claim 1 wherein the inner face of the at least one wall proximal the upper open end is frustoconical in shape, and wherein the lid side face is frustoconical in shape to mate with the inner face of the at least one wall proximal the upper open end.

11. The beverage container or kettle of 1 wherein the lid is formed with a raised grip.

12. The beverage container or kettle of claim 11 wherein the upper open end of the body defines a body upper surface, wherein the lid, when inserted into the open upper end of the body, registers against the inner surface of the inner wall whereby the top surface of the lid is below the plane occupied by the body upper surface.

13. The beverage container or kettle of claim 1 further comprising a clip formed from a flexible material, wherein the clip registers against the lid and an outer surface of the body to secure the lid to the body.

14. The beverage container or kettle of claim 1, wherein the lid is formed with a raised grip, and wherein the upper open end of the body defines a body upper surface, wherein the lid, when inserted into the open upper end of the body, registers against the inner surface of the inner wall whereby the top surface of the lid is level with or below the plane occupied by the body upper surface.

15. A beverage container or kettle comprising: a body having a closed bottom end, an open upper end, and constructed from glass, wherein the body is formed with a double wall having an inner wall and an outer wall, wherein a wall gap is defined by an inner surface of the outer wall and an outer surface of the inner wall, wherein the closed bottom end is formed with an inner bottom wall and an outer bottom wall to form a double bottom wall with the inner bottom wall continuous with the inner wall and the outer bottom wall continuous with the outer wall, wherein a bottom gap defined by an inner surface of the outer bottom wall and an outer surface of the inner bottom wall is continuous with the wall gap, wherein a vent hole is formed or created in the outer bottom wall in fluid communication with the wall gap, and wherein an inner face of the inner wall proximal the upper end is formed from ground glass to form a first half of a discontinuous or interrupted glass joint; and, a lid having a top lid surface and a bottom lid surface spaced by a lid side face, wherein the lid is formed with a raised grip having a depression formed in a central portion of the grip and two raised areas formed on outer portions of the grip, wherein the lid side face is formed from ground glass to form a second half of the glass joint, wherein the lid side face mates with, and registers against, the inner face of the inner wall to form the glass joint when the lid is inserted into the upper open end of the body, and wherein the upper open end of the body defines a body upper surface, wherein the lid, when inserted into the open upper end of the body to form the glass joint, the top surface of the lid and/or the raised grip is level with or below the plane occupied by the body upper surface.

16. The beverage container or kettle of claim 15 wherein the inner surface of the inner wall proximal the upper open end is frustoconical in shape, and wherein the lid side wall is frustoconical in shape to mate with the inner wall proximal the upper open end.

17. The beverage container or kettle of claim 15 further comprising a clip formed from a flexible material, wherein the clip has an axially extended clip extension that registers against the top surface of the lid to maintain the lid in registration with the body when the clip is registered about an outer surface of the body.

18. The beverage container or kettle of claim 15 further comprising an inductively couplable layer is joined to, or secured to, the outer surface of the inner wall and/or to the outer surface of the inner bottom wall.

19. The beverage container or kettle of claim 18 further comprising at least one drinking port or channel formed in the lid that traverses the lid from the top lid surface to the bottom lid surface and at least one vent port or channel formed in the lid that traverses the lid from the top lid surface to the bottom lid surface.

20. The beverage container or kettle of claim 18 wherein the lid has portions defining a drinking port or side channel that extends from the top lid surface down to the bottom lid surface and partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face and other portions that define a vent port or vent channel that extends from the top lid surface down to the bottom lid surface partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face.

21. The beverage container or kettle of claim 15 further comprising a body wall closure secured in the vent hole.

22. The beverage container or kettle of claim 15 wherein the top lid surface, bottom lid surface and lid side wall define a cavity, wherein the cavity is filled with an insulating gas, wherein the insulating gas is selected from the group consisting of air, low-oxygen gas, low-pressure gas, low-conductivity gas and mixtures thereof.

23. The beverage container or kettle of claim 15 further comprising at least one drinking port or channel formed in the lid that traverses the lid from the top lid surface to the bottom lid surface and at least one vent port or channel formed in the lid that traverses the lid from the top lid surface to the bottom lid surface.

24. The beverage container or kettle of claim 15 wherein the lid has portions defining a drinking port or side channel that extends from the top lid surface down to the bottom lid surface and partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face and other portions that define a vent port or vent channel that extends from the top lid surface down to the bottom lid surface partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face.

25. A beverage container or kettle comprising: a body having a closed bottom end, an open upper end, and constructed from glass, wherein the body is formed with a double wall having an inner wall and an outer wall, wherein a wall gap is defined by an inner surface of the outer wall and an outer surface of the inner wall, wherein the closed bottom end is formed with an inner bottom wall and an outer bottom wall to form a double bottom wall with the inner bottom wall continuous with the inner wall and the outer bottom wall continuous with the outer wall, wherein a bottom gap defined by an inner surface of the outer bottom wall and an outer surface of the inner bottom wall is continuous with the wall gap, wherein an inductively couplable layer is joined to, or secured to, the outer surface of the inner wall and/or to the outer surface of the inner bottom wall, and wherein an inner face of the inner wall proximal the upper end is formed from ground glass to form a first half of a glass joint; and, a lid having a top lid surface and a bottom lid surface spaced by a lid side face, wherein a surface of the lid side face is formed from ground glass to form a second half of the glass joint, wherein the lid side face registers against the inner face of the at least one wall to form the glass joint when the lid is inserted into the upper open end of the body.

26. The beverage container or kettle of claim 25 wherein the inner surface of the inner wall proximal the upper open end is frustoconical in shape, and wherein the lid side wall is frustoconical in shape to mate with the inner wall proximal the upper open end.

27. The beverage container or kettle of claim 25 wherein the inner surface of the inner wall proximal the upper open end is frustoconical in shape, and wherein the lid side wall is frustoconical in shape to mate with the inner wall proximal the upper open end.

28. The beverage container or kettle of claim 25 further comprising a clip formed from a flexible material, wherein the clip has an axially extended clip extension that registers against the top surface of the lid to maintain the lid in registration with the body when the clip is registered about an outer surface of the body.

29. The beverage container or kettle of claim 25 wherein the upper open end of the body defines a body upper surface, wherein the lid is formed with a raised grip, and wherein the lid, when inserted into the open upper end of the body, registers against the inner surface of the inner wall whereby the top surface of the lid is level with or below the plane occupied by the body upper surface.

30. The beverage container or kettle of claim 25 wherein the top lid surface defines a first half recess and a second half recess, wherein the first half recess is formed with at least one through-bore, wherein the second half recess is formed with at least one through-bore.

31. The beverage container or kettle of claim 25 wherein the lid is formed with a raised grip, wherein the raised grip is ergonomically shaped with a depression formed toward a central portion of the raised grip and two raised areas formed near outer portions of the raised grip to allow for drinking with the glass joint engaged and for manipulation of the lid by hand to insert and extract the lid.

32. The beverage container or kettle of claim 25 further comprising at least one drinking port or channel formed in the lid that traverses the lid from the top lid surface to the bottom lid surface and at least one vent port or channel formed in the lid that traverses the lid from the top lid surface to the bottom lid surface.

33. The beverage container or kettle of claim 25 wherein the lid has portions defining a drinking port or side channel that extends from the top lid surface down to the bottom lid surface and partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face and other portions that define a vent port or vent channel that extends from the top lid surface down to the bottom lid surface partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face.

34. A beverage container or kettle comprising: a body having a closed bottom end, an open upper end, and constructed from glass having a coefficient of thermal expansion, wherein the body is formed with a double wall having an inner wall and an outer wall, wherein a wall gap is defined by an inner surface of the outer wall and an outer surface of the inner wall, wherein the closed bottom end is formed with an inner bottom wall and an outer bottom wall to form a double bottom wall with the inner bottom wall continuous with the inner wall and the outer bottom wall continuous with the outer wall, wherein a bottom gap defined by an inner surface of the outer bottom wall and an outer surface of the inner bottom wall is continuous with the wall gap, and wherein an inner face of the inner wall proximal the upper end is formed from ground glass to form a first half of a discontinuous or interrupted glass joint; a lid having a top lid surface and a bottom lid surface spaced by a lid side face, wherein the lid is formed with a raised grip having a depression formed in a central portion of the grip and two raised areas formed on outer portions of the grip, wherein the lid side face is formed from ground glass to form a second half of the glass joint, wherein the lid side face mates with, and registers against, the inner face of the inner wall to form the glass joint when the lid is inserted into the upper open end of the body, and wherein the upper open end of the body defines a body upper surface, wherein the lid, when inserted into the open upper end of the body to form the glass joint, the top surface of the lid and/or the raised grip is level with or below the plane occupied by the body upper surface; and, an inductive coupling layer joined to, or secured to, the outer surface of the inner wall, wherein the inductive coupling layer has a coefficient of thermal expansion matched to the coefficient of thermal expansion of the glass.

35. The beverage container or kettle of claim 30 wherein the inductive coupling layer is ferro magnetic or ferrimagnetic.

36. The beverage container or kettle of claim 30 wherein the inductive coupling layer is formed from an Iron, Nickel, Cobalt ally.

37. A beverage container or kettle comprising: a body having a closed bottom end, an open upper end, and constructed from glass, wherein the body is formed with at least one wall, and wherein an inner face of the at least one wall proximal the upper end is formed from ground glass to form a first half of a discontinuous or interrupted glass joint; a lid constructed from glass having a top lid surface and a bottom lid surface spaced by a lid side face, wherein the lid has portions defining a drinking port or side channel that extends from the top lid surface down to the bottom lid surface and partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face and other portions that define a vent port or vent channel that extends from the top lid surface down to the bottom lid surface partially defined by portions of the lid side face that creates a discontinuity or interruption in the lid side face, wherein the lid side face is formed from ground glass to form a second half of the discontinuous or interrupted glass joint, wherein the lid side face mates with, and registers against, the inner face of the at least one wall, except at the locations of the drinking port and the vent port, to form the discontinuous or interrupted glass joint when the lid is inserted into the upper open end of the body; and, an inductively couplable layer joined to, or secured to, an outer surface of the at least one wall and/or to an outer surface of the bottom end.

38. The beverage container of claim 37 wherein the lid has a cavity defined by the upper lid surface, the lower lid surface and the lid side wall.

39. The beverage container of claim 38 wherein at least one surface of the walls defining the cavity is coated with infrared-reflecting coating.

40. The beverage container of claim 38 wherein the cavity is filled with an insulating gas, wherein the insulating gas is selected from the group consisting of air, low-oxygen gas, low-pressure gas, low-conductivity gas and mixtures thereof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Various other objects, features and attendant advantages of the present disclosure will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the several views, and wherein:

[0048] FIG. 1 is an upper-perspective view in elevation of a travel mug according to one embodiment of the disclosure.

[0049] FIG. 2 is an upper-perspective, exploded view of the travel mug shown in FIG. 1.

[0050] FIG. 3 is an upper-perspective, exploded, cross-section view of the lid and the body of the travel mug embodiment shown in FIG. 1.

[0051] FIG. 4 is a magnified, perspective, cross-section view of the body of the travel mug embodiment shown in FIG. 1.

[0052] FIG. 5 is a top perspective view of lid according to another embodiment of the disclosure.

[0053] FIG. 6 is a top perspective, cross-section view of the lid shown in FIG. 5.

[0054] FIG. 7 is a side perspective, partial cross-section view of a travel mug or beverage container having a plugged vent hole according to another embodiment of the disclosure.

[0055] FIG. 8 is a side perspective, partial cross-sectional view of a travel mug or beverage container having an inductive coupler according to yet another embodiment of the disclosure.

DETAILED DESCRIPTION OF THE DISCLOSURE

[0056] Referring now to FIGS. 1-4, in one aspect of the disclosure, a beverage container designated generally as 10, includes a body 20 having an enclosed bottom end and an open upper end. Body 20 is constructed from glass that holds the beverage. A lid 30 is made of glass that prevents large-scale convective heat losses and spills. Lid 30 is secured to the open upper end of body 20. A clip 40 made of flexible material that prevents a jarring force from separating the body 20 from lid 30 is secured to, and registered against, body 20 and lid 30.

[0057] The lid 30 is sealed to body 20 at its upper end with a ground glass joint. The joint consists of a ground-glass outer face 31 on lid 30 and a ground-glass inner face 21 on body 20. The mating faces, 21 and 31, are frustoconical in shape with the surface angle the same on both faces to ensure substantially full registration between the surfaces, which maximizes the sealing function. The seal formed by the ground-glass joint is interrupted at two locations, a drinking port or drinking channel 32 and a venting port or vent channel 33. Drinking port 32 is configured to permit fluids to flow from beverage container 10 for drinking while venting port 33 relieves or neutralizes the vacuum created by the exiting fluid.

[0058] The thickness of lid 30 is set to significantly reduce heat loss by convection. In turn, both drinking port 32 and venting port 33 are long enough, the lengths of which are determined by the thickness of lid 30, to significantly reduce heat loss by convection. The length of the ports and thereto, the thickness of lid 30, by way of illustration and not limitation, may be greater than 4 mm and less than 40 mm. A range of from about 17 mm to about 23 mm may provide a good balance between lid thickness and heat retention in the beverage container. It is understood that a lid thickness at less than 4 mm and concomitant length of ports 32 and 33 will have little effect on reducing heat loss while a lid thickness above 40 mm will result in the travel mug 10 becoming too large, potentially unwieldy and uneconomical. A lid thickness and port lengths from about 17 mm to about 23 mm should provide an optimal balance between thermal insulation, scale, and cost. Drinking port 32 is positioned below the lip of body 23 to facilitate drinking from beverage container 10 with the lips pressed against body 20 so beverage fluid can be directed toward the mouth by face 21 and lip 23 while drinking.

[0059] Lid 30 has a raised grip 34, which is useful for installing and extracting lid 30 to and from body 20. Raised grip 34 is ergonomically shaped, with a depression 34a formed toward a central portion of raised grip 34, and with two raised areas 34b and 34c formed near outer portions of raised grip 34. The purpose of depression 34a is to create a void to accommodate the nose and philtrum while drinking. The purpose of the two raised areas, 34b and 34c, is to provide a larger portion to grasp raised grip 34.

[0060] The lid 30 is essentially a glass shell with from about a 1 mm to about a 3 mm wall thickness 35, and a cavity 36 defined by the walls of lid 35. Any portion of the walls of the lid may be coated with a thermally reflective coating. Lid 30 may also be left uncoated to maintain the materials natural transparency or translucency and enable viewing of the contents of the beverage container 10. The purpose of cavity 36 is to insulate an interior bottom surface 37 of lid 30 from an exterior surface 38 of the lid. Cavity 36 can contain air, vacuum, or a low conductivity gas, any of which provide an additional insulation factor.

[0061] Body 20 is a double-wall glass structure with an inner body wall 24 and an outer body wall 25, both with a thickness from about 1 mm to about 3 mm. A cylindrical body cavity 26 formed and defined by inner body wall 24 and outer body wall 25 insulates beverage fluids resident in body 20. Cavity 26 may be continuous with a bottom gap 26a formed between an inner of a base 27 and an outer base 28 that may be a continuous extension of an outer body wall 25 of body 20. The gap 26 breaks the conduction path for heat through inner and outer body walls, 24 and 25, of the beverage container by introducing a low-conductance barrier, such as air, vacuum, or other low conductivity gas. Optionally, a radially outer surface 24A of the inner body wall 24 and/or a radially inner surface 25A of outer body wall 25 is coated with a continuous and high-reflectivity coating 29. Coating 29 reflects heat back to an enclosed warm beverage and away from an enclosed cool beverage, thereby providing additional thermal insulation. Coating 29 may also be patterned with an artistic design.

[0062] As shown in FIGS. 1 and 2, when lid 30 is installed in body 20, an optional clip 40 can be installed to secure lid 30 to the body 20. A clip extension 41 extends axially from clip 40 where clip 40 attaches at an upper-portion 22 of the side of body 20 and reaches around a lip 23 of body 20 and applies a downward force on an exterior 38 of lid 30. Clip extension 41 has a curl 42 at the point where it presses on lid exterior 38 to distribute the load more evenly and to finish the end of clip extension 41. An upward reaction force imparted by lid 30 on clip 40 is opposed by the connection of clip 40 to body 20, which is established by two secondary clip extensions, 43a and 43b, that wrap around the circumference of an upper portion 22 of body 20. In an alternative embodiment, upper portion 22 of body 20 has a rising and expanding taper, which prevents clip 40 from sliding up body 20 and reducing the retaining force exerted on lid 30.

[0063] The disclosure also conceives other methods of attaching clip 40 and other possible shapes for body 20 including a straight cylinder. Body 20 can take on the shape of any regular or irregular geometric shape in cross-section and remain within the scope of the disclosure. The ends of secondary extensions 43a and 43b have curls, 44a and 44b, respectively, to facilitate installing and removing clip 40 and to finish the ends of the extensions 43a and 43b. Clip 40 may be formed from an elastic metal with high-yield strength to facilitate installation and removal without permanent deformation.

[0064] In another aspect of the disclosure, a modified an alternative lid 50 is sealed to body 20 with a ground glass joint. The joint consists of a ground-glass face 51 on lid 50 and a ground-glass face 21 on the body 20. The mating faces, 21 and 51, are frustoconical in shape and are formed with the same angle so that registration between the faces is maximized over the full extent of the mating surface area. Alternative lid 50 is formed with a plurality of holes or through-bores 52 on a first half of alternative lid 50 and at least one hole or through-bore 53 formed on and defined by a second half of alternative lid 50, wherein the plurality of holes 52 on the first half of alternative lid 50 act as a strainer for loose leaf tea or similar beverage and the at least one hole 53 on the second half of alternative lid 50 functions as a vent hole. One or both the first half and the second half of alternative lid 50 may be recessed as shown in FIG. 6 to receive fluids, solids and/or mixtures thereof. Alternative lid 50 also sits below the lip of the body 23 to facilitate drinking from beverage container 10 with the lips pressed against body 20 so beverage fluid can be directed toward the mouth by face 21 and lip 23 while drinking.

[0065] Referring now to FIG. 7, in another aspect of the disclosure, a dual-walled travel mug, fluid container or vessel, designated generally as 10′ includes a body 20′ having a double-wall glass structure with an inner body wall 24′ and an outer body wall 25′, both with a thickness from about 1 mm to about 3 mm. As used herein, identical reference characters having differently primed or unprimed variations and assigned to features of the disclosure are intended to identify different embodiments of the same feature. A cylindrical body cavity 26′ formed and defined by inner body wall 24′ and outer body wall 25′ insulates beverage fluids resident in body 20′. Cavity 26′ may be continuous with a bottom gap 26A′ formed between an inner of a base 27′ and an outer base 28′ that may be a continuous extension of an outer body wall 25′ of body 20′. The gap 26′ breaks the conduction path for heat through inner and outer body walls, 24′ and 25′, of the beverage container by introducing a low-conductance barrier, such as air, vacuum, or other low conductivity media.

[0066] In forming travel mug, fluid container or vessel 10′, joining and sealing the two walls at their tops is performed by applying heat to the tops while mechanically bringing the tops into registration. By using heat, which can be applied via flame, a partial vacuum is created in gap 26′ when container 10′ cools. This introduces potential energy against the container walls that can cause breakage or failure of the wall integrity and strength. One method to alleviate or prevent the development of a vacuum in the glass-enclosed cavity or gap 26′ is to provide a vent hole in fluid communication with the glass-enclosed cavity. To achieve this, base 28′ is formed with a vent hole 59′ created during the formation of outer wall 25′ and base 28′ or created in base 28′ after wall and base formation via a boring tool such as a small focused flame or a drill and drill bit. It should be understood that vent hole 59′ also may be formed at any location on outer body wall 25′ and remain within the scope of the disclosure. Vent hole 59′ provides fluid communication between gap 26′ and the atmosphere outside body 20′. This prevents the formation of a vacuum or a partial vacuum in gap 26′ to ensure no potential energy is applied to the walls of dual-walled mug, container or vessel 10′ during its formation or during its cooldown phase of construction. Once the container 10′ is cooled into its final form, vent hole 59′ may be occluded and sealed with a body wall closure 60′ that may be in the form of a plug constructed from glass, metal, ceramic, natural and/or polymeric material. Closure 60′ may be secured in vent hole 59′ via friction fit, mechanical interlock, or chemical bonding via the material used to form closure 60′ flowing about and encasing the portions of base 28′ defining vent hole 59′.

[0067] Optionally, a radially outer surface 24A′ of the inner body wall 24′ and/or a radially inner surface 25A′ of outer body wall 25′ is coated with a continuous and high-reflectivity coating 29′. Coating 29′ reflects heat back to an enclosed warm beverage and away from an enclosed cool beverage, thereby providing additional thermal insulation. Coating 29′ may also be patterned with an artistic design.

[0068] Referring now to FIG. 8, in a still further aspect of the disclosure, a dual-walled travel mug, fluid container or vessel, designated generally as 10″ includes a body 20″ having a double-wall glass structure with an inner body wall 24″ and an outer body wall 25″, both with a thickness from about 1 mm to about 3 mm. A cylindrical body cavity 26″ formed and defined by inner body wall 24″ and outer body wall 25″ insulates beverage fluids resident in body 20″. Cavity 26″ may be continuous with a bottom gap 26A″ formed between an inner base or inner bottom wall 27″, which may be continuous with inner body wall 24″, and an outer base or outer bottom wall 28″, which may be a continuous extension of an outer body wall 25″. The gap 26″ breaks the conduction path for heat through inner and outer body walls, 24″ and 25″, of the beverage container by introducing a low-conductance barrier, such as air, vacuum, or other low conductivity gas.

[0069] Although the dual-walled configuration of container 10″ provides a good insulation factor, it is not perfect and heat loss will be experienced over time. To retard or prevent beverage temperature loss, or to increase the beverage's temperature to a desired level, radially outer surface 24A″ of the inner body wall 24″ and circular outer surface 24B of the inner base 27″, are optionally joined with, or secured to, an inductively couplable layer 70″. Inductively couplable layer 70″ is conductive and may be ferromagnetic and ferrimagnetic. It should be understood that inductively couplable layer 70″ may be joined just to radially outer surface 24A″ alone, just to circular outer surface 24B alone, or continuously over both surfaces. In order to prevent the transmission of heat to outer body wall 25″ or outer base 28″, inductively couplable layer 70″ should not come into contact with this wall or this base. Of course, if desired to provide a heated outer surface, inductively couplable layer 70″ can be registered against outer body wall 25″ and/or outer base 28″.

[0070] Inductively couplable layer 70″ is optionally less than one micron thick to reduce thermal expansion mismatch stress in inner body wall 24″. Inductively couplable layer 70″ optionally can be constructed to have a thermal expansion coefficient matched to the thermal expansion coefficient of inner body wall 24″ to reduce thermal expansion mismatch stress. In one illustrative embodiment, inductively couplable layer 70″ is formed from a Fernico alloy constructed primarily of iron, nickel and cobalt with a non-limiting example of the composition being 29% nickel, 17% cobalt, less than 0.01 carbon, 0.2% silicon, 0.3% manganese, and the balance iron or 31% nickel, 15% cobalt, less than 0.01 carbon, 0.2% silicon, 0.3% manganese, and the balance iron that has a thermal coefficient of expansion that matches the coefficient of thermal expansion of borosilicate glass, one of the materials that can be used to form the travel mugs, containers, and vessels disclosed herein. One illustrative method of joining inductively couplable layer 70″ to the beverage container or vessel involves applying the inductively couplable layer to inner body wall 24″ by vapor deposition or other thin film forming technique when less than 1 mm, or inner body wall 24″ can be melted to join inductively couplable layer 70″ when present in thicker (greater than 1 mm), also known as bulk form. It should be understood that this inductive coupling feature has broad applicability and can be applied to any fluid-containing vessel, both single-walled and multi-walled, including illustratively travel mugs and kettles. It should be understood further that cavity 26″ may be a vacuum, filled with air or other insulating gas, or filled with another insulating media as described for other embodiments disclosed herein.

[0071] As described herein, the disclosed beverage containers may be constructed from glass materials. A particularly advantageous material is low-thermal-expansion borosilicate glass. The low thermal expansion property of this glass material helps to prevent the glass joint from binding and makes the vessel more stable against thermal shock. Borosilicate glass is also harder than the more common soda lime glass, a property that makes the joint surfaces more stable against wear. It should be understood that any glass material including glass made from silicates can be used to construct the disclosed beverage containers and remain within the scope of the disclosure.

[0072] To operate any of the embodiments of the disclosed beverage container 10, the user fills the interior chamber of body 20 with the desired beverage and places lid 30 on body 20, snuggly fitting the faces of the glass joint. And then, if additional security in the joint is desired, clip 40 may optionally be applied to the assembly with first curl 42 applied to lid 30 opposite the drinking port, and then secondary extensions 43a and 43b positioned around upper portion 22 of body 20. When the user is finished consuming their beverage, the assembly is disassembled in reverse order. If optionally installed, first clip 40 is removed by exerting a force against curls 44a and 44b at the ends of extensions 43a and 43b, to push them off lid 30 while simultaneously applying a removal pressure by using grip 34. For cleaning all the components, body 20, lid 30, and clip 40 can be machine washed in a dishwasher using a standard cycle with heated drying.

[0073] While the present disclosure has been described in connection with several embodiments thereof, it will be apparent to those skilled in the art that many changes and modifications may be made without departing from the true spirit and scope of the present disclosure. Accordingly, it is intended by the appended claims to cover all such changes and modifications as come within the true spirit and scope of the disclosure. What I claim as new and desire to secure by United States Letters Patent is