We claim the ornamental design for an upper frame of a track system for an all-terrain vehicle, as shown and described.
FIG. 1 is a perspective view of an upper frame of a track system for an all-terrain vehicle according to the present design;
FIG. 2 is a side elevational view of the upper frame of a track system for an all-terrain vehicle of FIG. 1;
FIG. 3 is a rear elevational view of the upper frame of a track system for an all-terrain vehicle of FIG. 1;
FIG. 4 is a front elevational view of the upper frame of a track system for an all-terrain vehicle of FIG. 1;
FIG. 5 is a top view of the upper frame of a track system for an all-terrain vehicle of FIG. 1;
FIG. 6 is a bottom view of the upper frame of a track system for an all-terrain vehicle of FIG. 1; and,
FIG. 7 is a side elevational view of the upper frame of a track system for an all-terrain vehicle shown in the context of its environment.
The outermost broken lines in the shape of a circle in FIGS. 1, 2, and 7 are boundary lines, while the other broken lines illustrate unclaimed environmental structure. None of the broken lines form part of the claimed design.