Input: pink crank rotating continuously.
Output: blue piston performing a linear oscillation.
The oscillation position can be adjusted by setting the angular position of the orange eccentric. The piston stroke length is kept almost unchanged.
The setting can be carried out without stopping the input motion.
This video was made based on picture , page 594 of the Russian book: С. Н. Кожевников и другие, Механизмы, Москва, 1965.