Cooking container and manufacturing method therefor

A cooking container comprising:

• an outer shell having an opening and a first flange;
• an inner shell having a second flange and being disposed inside the outer shell through the opening, forming a wall space between the outer and inner shells, wherein the wall space is formed substantially along the height of the inner shell and at least partially contains air, wherein an inner bottom surface of the outer shell and an outer bottom surface of the inner shell are affixed to each other to allow even distribution of heat through out the bottom surface of the inner shell;
• and
• a heat conduction plate affixed to and in contact with an outer bottom surface of the outer shell, wherein the first and the second flanges of the outer and inner shells are curled at about 360 degree angle and at least four times to form a rolled joint to hermetically seal the wall space.

A method of manufacturing a cooking container having outer and inner shells forming wall and bottom spaces between the outer and inner shells, the wall space being formed substantially along the height of the inner shell, the method comprising the steps of:

• placing upright the outer shell on a concaved mold, the outer shell having a flange;
• placing a predetermined amount of the heat conductive medium into a space defined by the outer shell placed on the first mold;
• placing upright the inner shell in the outer shell so that the heat conductive medium at least partially surrounds the inner shell, the inner shell having a flange placed substantially parallel to the flange of the outer shell, wherein a convexed mold is placed in the inner shell to firmly hold the inner shell with respect to the outer shell;
• and
• forming a rolled joint by curling together the flanges of the outer and inner shells at about 360 degree angle and at least four times to prevent the heat conductive medium from being discharged from the space even when the cooking container is exposed to heat, wherein the curling of the flanges of the outer and inner shells is carried out by placing at least one curling roller against the flanges while rotating the outer and inner shells with respect to the curling roller.