Patent ID: 7265475

Claim:
A two speed direct current electric motor comprising: an armature having a commutator, said commutator adapted to receive an electromotive force to cause said armature to operatively rotate; a brush assembly having a common brush and a low-speed brush that is disposed about and in electrical communication with said commutator and adapted to provide a first electromotive force to cause said armature to provide a low-speed rotational output; said brush assembly further including a high-speed brush having a convex shaped end in physical and electrical communication with said commutator to provide a second electromotive force to cause said armature to provide a high-speed rotational output, said high-speed brush radially offset from said commutator such that said convex shaped end and said radial offset of said high-speed brush provide an electrically resultant contact point with respect to said commutator that is off center of said high-speed brush so that the drag placed on said armature by the contact of said high-speed brush on said commutator is reduced, said convex shaped end of said high-speed brush further adapted to wear to take the shape of said commutator, said electrically resultant contact point located at a first predetermined angular distance from an electrical contact point of said low-speed brush such that said electrically resultant contact point moves angularly closer to said electrical contact point of said low-speed brush and said high-speed rotational output of said armature decreases as said high-speed brush wears.