Patent ID: 6683396
Filing Date: 2004-01-27
Classification: B25F,H02K

Abstract:
A portable motor powered device comprising:a housing accommodating a DC motor which operates selectively at two different DC voltages; a cordless battery pack detachably connected to said housing and having a battery which supplies a low DC voltage for operating said DC motor; a corded power pack detachably connected to said housing and supplying a high DC voltage for operating said motor, said corded power pack having a power cord adapted to be connected to receive an AC source voltage and a converter for converting said AC source voltage into said high DC voltage; wherein said DC motor includes a rotor provided with a first winding and a second winding, said first winding being coupled to receive said low voltage for driving said DC motor, and said second winding being coupled to receive said high voltage for driving said DC motor; said housing includes a power switch for connecting said low and high DC voltages to said first and second windings, respectively, said rotor including a core provided with said first and second windings and a rotor shaft extending through said core, said rotor shaft carrying first and second commutators respectively connected to said first and second windings, said first and second commutators being disposed on opposite sides of said core to be spaced axially along said rotor shaft and being in contact with first and second brushes which supply currents respectively from said low and high DC voltages, said first brush being connected to said power switch through a low voltage line, said second brush being connected to said power switch through a high voltage line, said low voltage line being routed within said housing a shorter path than said high voltage line.