Gas filling apparatus

FIG. 1 is a front elevational view of the gas filling apparatus of the present invention showing our new design, the broken lines in the drawing forming no part of the claimed design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a right side elevational view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a top plan view thereof;

FIG. 6 is a bottom plan view thereof; and,

FIG. 7 is a top, front perspective view thereof, the broken lines in the drawing forming no part of the claimed design.