Motor with integral constant torque clutch

Claim 2

A motor for producing an output torque which is limited to a predetermined value, including in combination: a housing for the motor; a stator mounted within the housing; a rotor located adjacent said stator and cooperating therewith to cause rotation of said rotor; a clutch drum rotatably mounted in the housing and including a cylindrical surface concentrically arranged with said rotor; a shaft rotationally mounted in the housing and axially aligned with the axis of said clutch drum; said rotor being rigidly attached to one of said clutch drum and said shaft for rotating the same; and slip torque clutch means engaging said cylindrical surface of said clutch drum and coupled to said shaft for coupling a predetermined maximum torque between said clutch drum and said shaft.

Claim 3

The combination according to claim 1 wherein said motor is a synchronous motor.

Claim 4

The combination according to claim 1 wherein said rotor is attached to said clutch drum and said shaft is the output shaft for the motor.

Claim 5

The combination according to claim 3 further including a flywheel attached to said output shaft and located within said housing.

Claim 6

The combination according to claim 1 wherein said slip torque clutch means includes: an arcuate clutch spring pressed upon the inner surface of said clutch drum and extending about said inner surface over an arc greater than 180* and resiliently biased outwardly into engagement with the inner surface of said clutch drum, said spring having a projection on at least one end; and a lever attached to said shaft for engagement with said projection on said clutch spring, with said spring projection, and said lever coupling said clutch drum to said shaft for rotation together, said spring providing firm engagement with the inner surface of said clutch drum for loads coupled to the motor requiring less than said predetermined maximum torque and said spring slipping relative to said clutch drum for loads demanding torque in excess of said predetermined maximum torque to cause only said predetermined maximum torque to be coupled between said clutch drum and said shaft.

Claim 7

The combination according to claim 5 wherein both ends of said spring are bent inwardly to form first and second projections extending toward the axis of said clutch drum.

Claim 8

The combination according to claim 5 wherein said stator is concentrically arranged outside of said clutch drum.

Claim 9

The combination according to claim 7 wherein said rotor is attached to said clutch drum and said shaft is the output shaft for the motor, and further including a flywheel fixed to said output shaft within said housing.

Claim 10

The combination according to claim 8 wherein said flywheel has the shape of a cylinder open at one end and extends over said stator to minimize magnetic flux leakage from the motor.