The ornamental design for a seatframe, as shown and described.
FIG. 1 is a perspective view of a first embodiment of a seat frame in accordance with the new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a right side elevational view thereof, a left side elevational view being a mirror image thereof;
FIG. 4 is a top view thereof;
FIG. 5 is a perspective view of another embodiment of a seat frame in accordance with the new design having arms which is the sole difference between it and FIGS. 1 through 4;
FIG. 6 is a front elevational view thereof;
FIG. 7 is a right side elevational view thereof, a left side elevational view being a mirror image thereof; and,
FIG. 8 is a top view thereof.
The broken lines in the figures are for illustration purposes only and form no part of the claimed design.