The ornamental design for a hand-operable vacuum pump, as shown and described.
FIG. 1 is a top perspective view of a hand-operable vacuum pump showing my new design, with the pump being connected to a vacuum chamber by way of a detachable tube.
FIG. 2 is a bottom perspective view thereof.
FIG. 3 is a front elevation view of thereof.
FIG. 4 is a rear elevation view thereof.
FIG. 5 is a right side elevation view thereof.
FIG. 6 is a left side elevation view thereof.
FIG. 7 is top view thereof; and,
FIG. 8 is a bottom view thereof.
The broken lines showing the detachable tube and vacuum chamber are for environmental purposes only and form no part of the claimed design.