FIG. 1 is a perspective top view of a lifting column showing our ornamental design, when in a retracted state,
FIG. 2 is a perspective bottom view thereof,
FIG. 3 is another perspective top view thereof,
FIG. 4 is another perspective bottom view thereof,
FIG. 5 is an elevational left side view thereof,
FIG. 6 is an elevational front view thereof,
FIG. 7 is an elevational right side view thereof,
FIG. 8 is an elevational rear view thereof,
FIG. 9 is a bottom plan view thereof,
FIG. 10 is a top plan view thereof,
FIG. 11 is a perspective top view thereof when in an extended state,
FIG. 12 is a perspective bottom view thereof when in an extended state,
FIG. 13 is another perspective top view thereof when in an extended state,
FIG. 14 is another perspective bottom view thereof when in an extended state,
FIG. 15 is an elevational left side view thereof when in an extended state,
FIG. 16 is an elevational front view thereof when in an extended state,
FIG. 17 is an elevational right side view thereof when in an extended state; and,
FIG. 18 is an elevational rear view thereof when in an extended state.