Abstract: In accordance with one aspect of the invention, a folding section of a mobile communication device comprises: an upper cover; a lower cover rotatably connected to a main body and engaged with the upper cover; an engaging portion formed between the upper cover and the lower cover for connecting the upper and lower covers, wherein the engaging portion comprises: a hook part protruding from the inner surface of the upper cover; and a hook engaging part formed at the lower cover facing the upper cover for engaging the hook parts; and a cap inserted into the hook engaging part so as to prevent the hook part from releasing from the hook engaging part.

Abstract: In accordance with one aspect of the invention, a folding section of a mobile communication device comprises: an upper cover; a lower cover rotatably connected to a main body and engaged with the upper cover; an engaging portion formed between the upper cover and the lower cover for connecting the upper and lower covers, wherein the engaging portion comprises: a hook part protruding from the inner surface of the upper cover; and a hook engaging part formed at the lower cover facing the upper cover for engaging the hook parts; and a cap inserted into the hook engaging part so as to prevent the hook part from releasing from the hook engaging part.

Abstract: A rotary head drum of a magnetic recording/playback apparatus having a back yoke integrated with a ring collar. The head drum includes a rotatable shaft, an upper rotary drum and a lower stationary drum which are mounted on upper and lower parts of the rotatable shaft, respectively. The back yoke integrated with the ring collar is mounted about the rotatable shaft under the lower stationary drum. The ring collar maintains a predetermined gap between a motor stator and a motor rotor. The motor stator is mounted about the rotatable shaft under the back yoke and the motor rotor is mounted on a lower surface of the ring collar. The motor housing is mounted on a lower surface of the lower stationary drum and made of a plastic material for absorbing a vibration.