Abstract: A metal container comprising a sheared portion in a part of the wall thereof, a projecting portion formed adjacent to the sheared portion and outwardly projecting from the wall of the container, the projecting portion having a fractured side surface and the dimension of the projecting portion in the direction transverse to the side surface increasing in the direction outwards of the container, and a gas introducing passage extending along the sheared portion and the fractured side surface and through the wall of the container.

Abstract: A method for filling gas into a container comprises the steps of forming a severed portion through the wall of the container, deforming outwardly a wall portion of the container adjacent to the severed portion so as to form a projecting portion, whereby a gas introducing passage communicating across the wall of the container is formed, supplying pressurized gas into the container through the passage, and deforming the projecting portion inwardly to close the gas introducing passage.

Abstract: A bit synchronization circuit which comprises a pulse generator for producing a pulse corresponding to a data signal received; a clock pulse oscillator for supplying a clock pulse having a frequency as high as four times the data speed of said data signal; a synchronization-controlling circuit supplied with signals from said pulse generator and clock pulse oscillator to produce a signal with a prescribed phase relative to a pulse delivered from said pulse generator; a ring counter whose reset terminal is supplied with an output signal from said synchronization-controlling circuit and whose count terminal is impressed with a clock pulse produced from said clock pulse oscillator; and a flip-flop circuit whose set terminal is supplied with the content "0" of said ring counter and whose reset terminal receives the content "2" thereof, thereby generating an output pulse synchronous with said data signal received.