The drawing shows a Sangamo self-starting motor, but the patent states it is applicable to manual start motors as well. The auxiliary movement is watch movement with balance wheel. A pivoted lever is operated by the magnetic field of the motor to stop the balance wheel when the motor is operating, and letting the balance wheel operate when the motor stops due to a power outage. One arm of the lever touches the balance wheel with a wiping motion to ensure that it starts and stops reliably. The electric movement has large hands and large numbers on the dial. The watch movement has small hands and small numbers on the dial. The hands of the watch movement will indicate how long the power outage was. After a power outage, the correct time is determined by the time on the large hands PLUS the time on the watch hands from the 12:00 or zero starting point. A special setting knob sets the watch hands back to the starting point and advances the clock hands the same amount, allowing the clock to be set to the correct time after one or more power outages.
