The invention is a mobile communication device, comprising a casing, N groups of elastic plugs and a keyboard, where the casing has a groove formed on its top surface; these elastic plugs are placed in the groove; and the keyboard is rotably equipped on the groove; and N guide grooves are formed on its bottom surface, where each guide groove corresponds to one group of elastic plugs, respectively; and the keyboard also comprises N groups of first contact points and N groups of second ones, where each group of first contact points and each group of second ones are placed in the corresponding guide grooves, respectively. When the keyboard is in the first position, each group of elastic plugs will contact with the corresponding first contact points. And when the keyboard rotates from the first position to the second position, each group of elastic plugs will contact with the corresponding second contact points. |