Patting me / cups

When there is hot water in the cup, some small water drops will be condensed on the cup cover. When we open the cup cover, these water drops will always drop on our hands or desk, which causes a lot of troubles. The inwall of cup cover is designed into circular arc. Before opening the cover, just pat it gently, then the water droplets will fall along the cambered surface into the cup, thus the design has effectively solved the trouble when drinking a cup of hot water.