US Patent 10181671 Opening/closing plug device

A foldable plug device includes a pin module having at least one fixed pin. A first articulating shaft is disposed in a bottom of the pin module, and a first casing and a second casing are disposed at two sides of the pin module. A slot is disposed in a middle portion of the first casing. A movable pin corresponding to the fixed pin is disposed at the second casing, and the movable pin is configured such that the movable pin is located in the slot when the two casings are folded, and the movable pin is turned out of the slot when the two casings are unfolded, to form a plug cooperating with the fixed pins.