We claim the ornamental design for a drip coffee machine, as shown and described.
FIG. 1 is a front perspective view of a drip coffee machine showing a new design:
FIG. 2 is a bottom perspective view thereof;
FIG. 3 is a front view thereof;
FIG. 4 is a rear view thereof;
FIG. 5 is a left-side elevation view thereof;
FIG. 6 is a right-side elevation view thereof;
FIG. 7 is a top plan view thereof;
FIG. 8 is a bottom plan view thereof; and,
FIG. 9 is a perspective view showing a state of use thereof.
The broken lines in FIG. 9 are for environment purpose only and form no part of the claimed design. The broken lines shown in the drawings depict environmental subject matter that forms no part of the claimed design.