We claim the ornamental design for a tracheal dilator, as shown and described.
FIG. 1 is a front/right/bottom perspective view of a tracheal dilator of the present invention;
FIG. 2 is a bottom view of the tracheal dilator of FIG. 1;
FIG. 3 is a top view of the tracheal dilator of FIG. 1;
FIG. 4 is a right side view of the tracheal dilator of FIG. 1, the left side view being a mirror image of the right side view shown;
FIG. 5 is a rear view of the tracheal dilator of FIG. 1; and,
FIG. 6 is a front view of the tracheal dilator of FIG. 1.
The dot dash broken lines immediately adjacent the shaded areas represent the bounds of the claimed design while all other evenly dashed broken lines are directed to environment and are for illustrative purposes only; the broken lines form no part of the claimed design.