Published on February 2, 2018
The cyan input shaft rotates two directions but the transmission is possible only for one by the pink spring.
The rotation direction that tends to wind the pink spring is transmitted to the yellow output shaft due to friction force between the pink spring and the shafts.
The blue bush is stationary. The orange spring is for keeping the yellow output shaft immobile when it stops.
The helix springs need not be fastened at either end; a slight interference fit is acceptable.
The spring helix direction is the key factor for this mechanism.
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