Commutating machine with integral speed control

Claim 1

In combination in an electro-dynamic commutating machine, a rotor rotatable about an axis; a commutator concentric and rotatable with said rotor; a plurality of commutator bars on the commutator; a plurality of windings on said rotor between respective pairs of the commutator bars; insulation separating the commutator bars; a pair of stationary brushes in sliding contact with said commutator; each of said brushes at all times contacting at least a respective one of the commutator bars determined by the instantaneous angular position of the commutator with respect to said brushes whereby a continuous power circuit from one to another of the brushes comprises a first of said commutator bars, at least one of the windings and a second of said commutator bars; and characterized by an interruptable sensing circuit comprising a stationary conducting sensor in sliding contact with said commutator; the area of contact between said sensor and the commutator being substantially narrower than the spaces between adjacent portions of said commutator bars coming into sliding contact with the sensor; the insulation in said spaces breaking contact between said sensor and the adjacent commutator bars.