The ornamental design for a crimper for smoothsquare cornered downspouts, as shown and described.
FIG. 1 is a perspective view of a crimper for smooth square cornered downspouts showing my new design;
FIG. 2 is a left side elevation thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a bottom view thereof;
FIG. 5 is a top view thereof;
FIG. 6 is a right side elevation thereof; and,
FIG. 7 is a rear view thereof.
The broken lines in the figures are included for the purpose of illustrating unclaimed portions of the crimper for smooth square cornered downspouts and form no part of the claimed design.