Insulated Cooking Vessel
A dual wall cooking vessel has an inner cooking portion or shell with a thermally conductive outer cladding that terminates prior to the interior of the rim of the cooking vessel. The construction provides uniform temperature during the cooking process, yet minimizes heat loss after cooking.
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The present application is a Division of and claims the benefit of priority to the US Non-provisional patent application having Ser. No. 11/953,153, which was filed on 10 Dec. 2007 under the title “Insulated Cooking Vessel”, which in turn claims the benefit of priority to the US provisional patent application having Ser. No. 60/871,357, which was filed on 21 Dec. 2006 under the title “Insulated Cooking Vessel”, both of which are incorporated herein by reference.
BACKGROUND OF INVENTIONThe present invention relates to an improved article of cookware, and in particular a cooking vessel having hollow sidewalls for insulation.
Prior methods of forming a cooking vessels having hollow walls for insulation involves a separate forming and bonding of two cookware vessels.
Prior forms of hollow wall cooking vessels have inferior cooking performance to the extent that the most of the heating of the foodstuffs is that the bottom of the cookware vessel, as the sidewalls are not intended to conduct heat, but rather provide insulation.
It is therefore a first object of the present invention to provide improved hollow wall cooking vessels wherein the cooking performance is not compromised by the insulating qualities, and the insulating qualities are not compromised by the cooking performance.
It is a further objective of the present invention to provide a method for forming such a cookware article.
It is still yet another object of the present invention to provide a method of forming a cookware article having attributes of the other objectives wherein the process of welding is not required to seal the hollow wall. A still further objective of the present invention is to provide a method of forming a cookware article having the attributes of the other objectives wherein there is provided in the lower portion of the sidewalls between the inner and outer vessel a sufficient mass of thermally conductive material to avoid damage or discoloration from the heating element or flame.
SUMMARY OF INVENTIONIn the present invention, the first object is achieved by providing a dual wall cooking vessel having a sealed insulating gap between the interior and exterior wall wherein the interior wall is a laminated structure with a substantially thermally conductive laminated layer facing the sealed insulating gap.
A second aspect of the invention is characterized in that the hollow wall cooking vessel is formed by first drawing a high walled vessel from one or more planar sheet of metals, and then reversed rolling the central portion of the bottom of the high walled vessel wherein the upper portion of the wall in the initial vessel becomes the exterior wall of the dual walled vessel and the lower portion of the high wall becomes the interior wall of the dual walled vessel.
The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of the embodiments thereof taken in conjunction with the accompanying drawings.
Referring to
In accordance with the present invention,
Generally, the first step in a process of forming the cooking vessel 100 at least one substantially planar sheet of metal is deep drawn to form a fluid containing pre-form vessel 50, shown in
Following the creation of pre-form vessel 50, a reverse drawing process deforms the bottom portion 59 inward, which is downward in the illustration, such that the bottom 59 and a portion of the surrounding walls 51 are inverted to form the work piece 50′, which has the nascent interior cooking surface 111 and inner walls 210 of shell 110 as well as the outer wall 220 of outer shell 120. The rim 130 integrally connects to the inner shell 110 to the outer wall 220 of outer shell 120. This inverted drawing process provides an open gap 150′ between the inner upright walls 210 and outer wall 220.
It should be noted that the drawing die used to form the inner walls 210 has a smaller diameter than the pre-form vessel 50 formed in the first step in the drawing process. Thus, the work piece 50′, shown in
In one alternative embodiment it is possible to form a completed dual wall vessel 100 from the work piece 50′, as shown in
However, more preferred methods are shown in
It should be noted that plate or dish 201 preferably has an outward concavity matching the exterior bottom disk 219, rather than being a flat plate. In the next step, as shown in
Optionally, as shown in
It should also be appreciated that impact bonding is also the preferred means to join the second disk or dish 202 in the step shown in
Alternatively, first disc 201 can be a shallow concave dish with sidewalls that extend the desired height to fill the lower portion 251 of gap 150. Either method provides a thick interlayer of a thermally conductive material to fill the bottom portion 251 of the gap 150 between the inner and outer vessel at the margin between bottom cooking surface and surrounding sidewalls. Fillings a lower portion of the sidewalls between the inner 110 and outer shell 120 in the above, or any other manner, provides sufficient thermal mass to avoid damage or discoloration from the heating element or flame. It should be appreciated that although impact bonding provides this significant benefit when the first bottom disk 201 is aluminum, impact bonding need not be the exclusive means adjoining a first bottom disk of aluminum, or any other material, with a second bottom disk of an other material. The cooking vessel of
As will be evident from
Next, as shown in
It is also preferable that another metal plate or disc 583 is bonded between the inner shell 513 and outer shell 520 by impact bonding prior to the attachment of rims 530 and 533, forming vessel 100 in
Again it should be emphasized that the cooking vessels 100 illustrated with respect to
While the invention has been described in connection with a preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth, but on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be within the spirit and scope of the invention as defined by the appended claims.
Claims
1. A dual wall cooking vessel, the vessel comprising:
- a) a vertical portion having, i) an internal bottom cooking surface, and ii) an exterior bottom surface,
- b) a seamless substantially upright wall having, i) an interior wall that surrounds and is connected at the bottom thereof to the internal bottom cooking surface, wherein the internal bottom cooking surface and the interior wall provide an inner vessel capable of containing fluid having a rim, and ii) an exterior wall that is a substantially downward continuation from the top of the interior wall wherein the interior and exterior walls meet at the rim, in which the exterior wall terminates by connecting to the exterior bottom surface of the vertical portion, wherein the exterior wall is spaced apart from the interior wall to form an annular cavity there between,
- c) wherein the inner vessel has a laminated construction wherein an inner surface is a first material and an outer surface is a more thermally conductive material than the first material, the more thermally conductive material surrounding at least the interior wall vertical walls and terminating below the rim so as to face the cavity formed between the interior wall and the exterior wall.
2. A dual wall cooking vessel according to claim 1 wherein the first material is stainless steel and the more thermally conductive material comprises one or more layer of at least one of copper and aluminum.
3. A dual wall cooking vessel according to claim 1 further comprising a first metal cap as the exterior bottom surface wherein the bottom of the exterior wall is bonded to the first metal cap.
4. A dual wall cooking vessel according to claim 3 further comprising a second metal cap that is bonded to the first metal cap wherein the bottom of the outer vessel wall is bonded between the first and second metal caps such that the second metal cap provides the exterior bottom surface.
5. A dual wall cooking vessel according to claim 4 wherein at least one of the first and second metal caps consists essentially of a metal selected from the group consisting of copper and aluminum.
6. A dual wall cooking vessel according to claim 4 wherein the second metal cap is a ferromagnetic material.
7. A dual wall cooking vessel according to claim 1 the more thermally conductive material surrounds the interior wall and the internal bottom cooking surface.
8. A dual wall cooking vessel according to claim 1 wherein the vertical portion has 2 or more layers and the bottom of the interior wall is bonded between said two of more layers.
9. A dual wall cooking vessel according to claim 2 further wherein the exterior bottom surface is bonded between the first metal cap and the portion of at least one of the vertical portion and seamless upright wall in a portion in the vicinity of connection of the vertical portion to the seamless upright wall that is external to the inner vessel.
10. A dual wall cooking vessel, the vessel comprising:
- a) an inner vessel having a bottom portion surrounded by vertical walls terminating at an inner rim to form an inner surface for containing fluids,
- b) an outer vessel having a bottom portion surrounded by vertical walls terminating at an outer rim to form an inner surface capable of containing fluids and surrounding the inner vessel,
- c) wherein the inner vessels is nested within the outer vessel such that the inner rim and the outer rim are concentrically aligned with each other, and
- d) wherein a cavity is formed between the inner surface of the outer vessel and the outer surface of the inner vessel by coupling the bottom of the outer vessel wall to the exterior bottom of the inner vessel,
- e) wherein the inner and outer rims are formed of the same continuous sheet of material that forms the outer vessel and the interior of the inner vessel.
11. A dual wall cooking vessel according to claim 10 further comprising a first metal cap that is bonded to the exterior bottom of the inner vessel wherein the bottom of the outer vessel wall is bonded to the first metal cap.
12. A dual wall cooking vessel according to claim 11 further comprising a second metal cap that is bonded to the first metal wherein the bottom of the outer vessel wall is bonded between the first and second metal caps.
13. A dual wall cooking vessel according to claim 12 wherein at least one of the first and second metal caps is selected from the group consisting of copper and aluminum.
14. A dual wall cooking vessel according to claim 11 wherein the second metal cap is a ferromagnetic material.
15. A dual wall cooking vessel according to claim 10 wherein at least the interior wall has a clad construction and the outer vessel is a unitary wall of a single metal layer.
16. A dual wall cooking vessel according to claim 10 wherein the vertical portion has 2 or more layers and the bottom of the interior wall is bonded between said two of more layers.
17. A dual wall cooking vessel according to claim 10 wherein at least one of said two or more layers is a ferromagnetic material.
18. A dual wall cooking vessel, the vessel comprising:
- a) a vertical portion having, i) an internal bottom cooking surface, ii) an exterior bottom surface,
- b) a seamless substantially upright wall having, i) an interior wall that surrounds and is connected at the bottom thereof to the internal bottom cooking surface, wherein the internal bottom cooking surface and the interior wall provide an inner vessel capable of containing fluid having a rim, ii) an exterior wall that is a substantially downward continuation from the top of the interior wall wherein the interior and exterior walls meet at the rim, in which the exterior wall terminates by connecting to the exterior bottom surface of the vertical portion, wherein the exterior wall is spaced apart from the interior wall to form an annular cavity there between,
- c) wherein the vertical portion has 2 or more layers and the bottom of the interior wall is bonded between said two of more layers.
19. A dual wall cooking vessel according to claim 18 further comprising a metal cap that forms the exterior bottom surface.
20. A dual wall cooking vessel according to claim 19 wherein at least one of 2 or more layers consists essentially of a metal selected from the group consisting of copper and aluminum.
21. A dual wall cooking vessel according to claim 19 wherein the metal cap is a ferromagnetic material.
Type: Application
Filed: Feb 22, 2011
Publication Date: Jun 16, 2011
Applicant: MEYER INTELLECTUAL PROPERTIES LTD. (Kowloon)
Inventor: Stanley Kin Sui Cheng (Hillsborough, CA)
Application Number: 13/032,237
International Classification: A47J 27/00 (20060101); A47J 36/00 (20060101);