The ornamental design for a handle for a vacuumpump, as shown.
FIG. 1 is a front perspective view of a vacuum pump showing my new design;
FIG. 2 is a front view thereof;
FIG. 3 is a rear view thereof;
FIG. 4 is a top plan view thereof;
FIG. 5 is a bottom plan view thereof;
FIG. 6 is a right side view thereof; and,
FIG. 7 is a left side view thereof.
The broken lines in FIGS. 2, 3, 5, 6 and 7 are included for the purpose of illustrating portions of the vacuum pump that form no part of the claimed design.