I claim, the ornamental design for a helmet, as shown and described.
The file of this patent contains at least one drawing/photograph executed in color. Copies of this patent with color drawing(s)/photograph(s) will be provided upon request and payment of the necessary fee.
FIG. 1 is a front elevational view, showing my new design;
FIG. 2 is a rear elevational view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a left side view thereof;
FIG. 5 is a bottom plan view thereof; and
FIG. 6 is a top plan view thereof;
FIG. 7 is a perspective view thereof;
FIG. 8 is a perspective view thereof with a visor in a closed position; and,
FIG. 9 is a perspective view thereof with an alternate visor in a closed position.