Spur gears have eccentric shafts. The eccentricity is e.
The slider's stroke length = 4e.
Yellow plates have rotary translational motion
This mechanism was taken from picture 9.41, page 670 of the Russian book: С. Н. Кожевников и другие, Механизмы, Москва, 1965.

STEP files of this video:
http://www.mediafire.com/download/co1...