The ornamental design for a billed capshapemaintainingdevice, as shown and described.
FIG. 1 is a front perspective view of a billed cap shape maintaining device depicted in an in-use state, showing my new design;
FIG. 2 is a front exploded view of the billed cap shape maintaining device;
FIG. 3 is a front view of the billed cap shape maintaining device;
FIG. 4 is a rear view thereof;
FIG. 5 is a left side view thereof;
FIG. 6 is a right side view thereof;
FIG. 7 is a top view thereof; and,
FIG. 8 is a bottom view thereof.
The long-short-long broken lines shown in FIG. 2 indicate the orientation of the components with regard to one another, and form no part of the claimed design. The uniform segmented broken lines in FIG. 1 illustrate the environment in which the article is used and form no part of the claim.