Input: pedal shaft (in grey).
Output: vertical shaft.
Two shafts are perpendicular to each other.
Axes of all revolution joints intersect at a common point.
The mechanism converts the input angular oscillation into the output continuous rotation.
The mechanism has two dead positions, when axes of all revolution joints are in a plane. The output inertia helps the mechanism overcome the dead points.
Orange weight keeps the pedal always at its upper position when not working.
Yellow disk cam and spring slider (in green) don’t allow the mechanism to stop at its dead points to ease its staring.
In case without the weight and the cam, turn the output a little when starting, if needed.