For driving the pulleys to polish them after they are turned the cone spindle is hollow at the rear end and receives a mandrel.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
If the bore of the work is coned, and of too great a cone to permit the mandrel to be driven, and drive the work by friction, the cone mandrel shown in Fig.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose
It is obvious, however, that work having a parallel bore may also be held by the cone mandrel, as shown in Fig.
"Modern Machine-Shop Practice, Volumes I and II"
Joshua Rose