A power actuable, openable and closable, lockable and unlockable, hinge assembly (1) is provided having pivot means (2), two hinge members (3, 4) pivotally interconnectable by the pivot means (2) for relative angular movement between an open position in which the hinge members (3, 4) extend substantially co-axially in end-to-end relationship and a closed position in which one hinged member is angularly displaced, with respect to the other hinge member, about the pivot means (2) out of the end-to-end relationship. Power drivable actuator locking means (7) are included having a first movable portion (8, 29) carried on one of the hinge members (3, 4) and a second co-operating movable portion (9, 30) carried on the other of the hinge members (3, 4) which power drivable actuator locking means (7) is selectively operable to open and lock the hinge members (3, 4) together in the substantially co-axial end-to-end open position relationship, and to unlock and close the hinge members (3, 4).