The ornamental design for a cable drum, as shown and described.
FIG. 1 is a front view of a design for a cable drum according to the present invention.
FIG. 2 is a top view of the cable drum of FIG. 1.
FIG. 3 is a bottom view of the cable drum of FIG. 1.
FIG. 4 is a right side view of the cable drum of FIG. 1.
FIG. 5 is a perspective view of the cable drum of FIG. 1.
FIG. 6 is a cross-sectional view of the cable drum taken along the line 6-6 of FIG. 4.
FIG. 7 is a cross-sectional view of the cable drum taken along the line 7-7 of FIG. 4.
FIG. 8 is a partial detail cross-sectional view taken in the region encircled by dashed lines in FIG. 6; and,
FIG. 9 is a partial detail cross-sectional view taken in the region encircled by dashed lines in FIG. 7.
The rear view of the cable drum is symmetrical to the front view of FIG. 1, and therefore is omitted. The left side view of the cable drum is symmetrical to the right side view of FIG. 4, and therefore is omitted.