| 摘要 |
<p>A lid for forming an airtight seal to a bowl or dish plate to elongate the life of product therein comprises an impermeable membrane having an outer perimeter larger than the rim of the container and an enforcement ring for enabling the formation of an airtight seal between the membrane and rim of the container under vacuum. The membrane is sufficiently soft to cause it to fill the lower sections or imperfections on the rim, thus enabling the lid to form an airtight seal to almost all household containers. The membrane may be adapted to have sufficient low tensile stress, thereby preventing the vacuum in the container from imploding or collapsing the container even if it has a thin or weak wall. The enforcement ring has vertical and horizontal rings connected to the membrane perimeter to prevent the membrane deformation at both vertical and horizontal directions. The lid may further comprise an air evacuation passageway having an air collection chamber for extracting air from the container and a valve for allowing air to flow out of the container but preventing air from entering. In use, the lid may be sealed to a container by simply pushing the membrane into the container and releasing the membrane to generate a vacuum to affix the membrane to the container, or may be sealed to a container by connecting a vacuum generator to the evacuation passageway to evacuate the container.</p> |
