FIG. 1 is a perspective view of a combination pushchair frame showing my design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a rear elevational view thereof;
FIG. 4 is a left side elevational view thereof;
FIG. 5 is a right side elevational view thereof;
FIG. 6 is a top plan view thereof;
FIG. 7 is a bottom plan view thereof;
FIG. 8 is a side view thereof;
FIG. 9 is a side view thereof;
FIG. 10 is a side view thereof;
FIG. 11 is a side view thereof;
FIG. 12 is a side view thereof; and,
FIG. 13 is a side view thereof.
The broken lines FIGS. 8 through 13 are included for the purpose of illustrating structural environment and form no part of the claimed design.