Patent ID: 7870802

Claim:
A method for stopping and then later selectively restarting an output shaft which is connected to a rotating input shaft by a double crank four bar linkage, which has an input shaft crank with a crankpin, an output shaft crank with a crankpin and a coupler connecting the crankpins, with the crank radius on the input shaft substantially equal to the coupler length, the axes of the input shaft and output shaft substantially parallel, and beginning with the input shaft and output shaft offset less than the coupler length wherein the method to stop and later selectively restart comprises: a. stopping involves increasing the offset of the input shaft and output shaft to coupler length within 90 degrees after the output shaft axis, the input shaft axis and the input shaft crankpin are all substantially in the same plane and the input shaft crankpin is furthest from the output shaft, the offset is held constant while the coupler, driven by the input shaft crankpin, spins around the stationary output shaft crankpin, b. restarting involves decreasing the offset from coupler length beginning within 90 degrees after the output shaft axis, the input shaft axis and the input shaft crankpin are all substantially in the same plane and the input shaft crankpin is furthest from the output shaft, whereby the rotational energy of the output shaft stopping is transferred into the input shaft and kinetic energy needed to restart the output shaft is transferred from the input shaft.