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 drawings will be provided by the Office upon request and payment of the necessary fee.
FIG. 1 is a front left side perspective view of a helmet showing our new design, the front right side perspective being a mirror image thereof;
FIG. 2 is an enlarged front right side perspective view thereof, the enlarged front left side perspective being a mirror image thereof;
FIG. 3 is an enlarged left side view thereof, the enlarged right side being a mirror image thereof;
FIG. 4 is a front left side perspective view of a helmet showing our new design, shown in color, the front right side perspective being a mirror image thereof;
FIG. 5 is an enlarged front right side perspective view thereof, the enlarged front left side perspective being a mirror image thereof; and,
FIG. 6 is an enlarged side view thereof, the enlarged right side being a mirror image thereof.
The broken lines depicting a human form represent environmental subject matter that forms no part of the claimed design. The broken lines immediately adjacent to the photographic area represent the bounds of the claimed design and form no part thereof.