The ornamental design for a children's invertible hourglass timer seat, as shown and described.
FIG. 1 is a perspective of a children's invertible hourglass timer seat of the present design, shown with a child sitting on the stool in a disciplinary time-out situation;
FIG. 2 is a perspective thereof without the child;
FIG. 3 is a front elevation view of the children's invertible hourglass timer seat as in FIG. 2, the rear elevation view being a mirror image thereof;
FIG. 4 is a left side elevation view of the children's invertible hourglass timer seat as in FIG. 2, the right side elevation view being a mirror image thereof;
FIG. 5 is a top plan view of the children's invertible hourglass timer seat as in FIG. 2; and,
FIG. 6 is a bottom view of the children's invertible hourglass timer seat as in FIG. 2.
The child, the adult and the floor portion shown in dotted lines in FIG. 1 are shown for environmental purposes only, and form no part of the claimed design.
The internal wall and parts of the hourglass shaped mid portion , along with the circular seating surfaces on the end caps' tops of the stool seat and the shifting sand itself are also shown in dotted lines for environmental purposes only, and form no part of the claimed design.