We claim the ornamental design for a hanging chair stand, as shown and described.
FIG. 1 is a front perspective view of the hanging chair stand with a hanging chair shown in broken-lines, the hanging chair forming no part of the claimed design;
FIG. 2 is a second front perspective view of the hanging chair stand;
FIG. 3 is a third front perspective view of the hanging chair stand;
FIG. 4 is a rear perspective view of the hanging chair stand;
FIG. 5 is a side view of the hanging chair stand;
FIG. 6 is a front view of the hanging chair stand;
FIG. 7 is a rear view of the hanging chair stand;
FIG. 8 is a top view of the hanging chair stand; and,
FIG. 9 is a bottom view of the hanging chair stand.