| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent a lid from warping due to the steam heat of a poured hot water by forming the lid into an upside-down conical shape which indents to the inside of a container, and fixing a tab piece to the central section of the indented surface. SOLUTION: The peripheral edge of a conical-shape lid 20 is bonded to the edge of the opening surface of a cup-shape container 10 in such a manner that the conical lid 20 may become an upside-down pyramid-shape which indents with the vertex facing to the inside of the container 10. At the time of a hot water pouring, the lid 20 is turned up approx. halfway by gripping a tab section 22 on the lid peripheral edge, and after hot water is poured, the lid 20 is closed. Then, a tab piece 30 at the center of the lid 20 is pulled upward. By this motion, the lid 20 is inverted and becomes a regular conical shape wherein the central tip end faces upward, and the peripheral edge of the lid 20 is closely joined to the opening edge of the container 10. By this constitution, since the lid 20 when being made the regular conical shape with the vertex facing upward by being inverted after the hot water is poured, closely joins to the peripheral edge of the opening surface 11 of the container 10 while maintaining the original shape retaining force, a temperature in the container is prevented from decreasing by the entering of air due to the turning back of the lid 20.</p> |
