The ornamental design for a double sided hemming apparatus, as shown and described.
FIG. 1 is a top plan view of the double sided hemming apparatus in accordance with my invention;
FIG. 2 is a bottom plan view of FIG. 1;
FIG. 3 is a first side view of FIG. 1, the opposite side being a mirror image thereof;
FIG. 4 is a second side view of FIG. 1, the opposite side being a mirror image thereof; and,
FIG. 5 is an exploded perspective view thereof. The claimed design is directed to the assembled double sided hemming apparatus as shown in FIG. 1. The components are separated in FIG. 5 to show aspects of the design that may not be apparent in FIG. 1. The bottom side of the intermediate layer is a mirror image of the depicted top side. The broken lines at the top perimeter of the bottom release layer represent the bounds of the claim, and the broken lines connecting the sides of the separated layers are included to show the order of assembly. None of the broken lines form a part of the claimed design.