Round eccentrics 1 and 2 rotate about fixed axes A and B. Links 5 and 6 mount knives 3 and 4, and have collars a encircling eccentrics 1 and 2. Links 5 and 6 have flat surfaces b which slide along flat surfaces c of sliders 8 and 7. Sliders 7 and 8 move along fixed guide f. Eccentrics 1 and 2 have independent drives, they rotate with equal angular velocities and have equal angles of rotation in each position. When eccentrics 1 and 2 rotate in opposite directions, knives 3 and 4 have translational motion and cut the material.
$1450$LG,FD$