The ornamental design for an overcap for a containerclosure, as shown and described.
FIG. 1 is a top plan view of an overcap for a container closure showing my new design;
FIG. 2 is a partial cross-sectional right side view thereof taken in the direction of line 2-2 in FIG. 1;
FIG. 3 is an underplan view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a right side view thereof;
FIG. 6 is a rear view thereof;
FIG. 7 is a left side view thereof; and,
FIG. 8 is a cross-sectional view drawn to a larger scale, illustrating an in use engagement between a portion of the overcap for a container closure of FIG. 1 and a container closure drawn in broken lines.
The broken lines in FIG. 8 illustrating a container closure depict environment and form no part of the claimed design. All other broken lines depict portions of the overcap for a container closure that form no part of the claimed design.