Image Number 2 for United States Patent #6224340.
A fan retention system for a blower/vacuum securely retains the fan and creates an insulating barrier to prevent the operator from touching the functionally insulated armature shaft. A nut having interlocking ramps for interlocking with interconnecting portions on an abutting fan surface is provided. The interconnecting portions of the fan may be either ramps or recesses. Furthermore, the nut has a closed end for insulating the armature shaft from the operator.