Eccentric 1 rotates about fixed axis A. Connecting rod 2 has collar a encircling eccentric 1 and slot b along which pin E of link 3 slides. Link 3 is connected by turning pairs F and H to link 4 and piston rod 5. Link 4 turns about fixed axis G. When eccentric 1 rotates about axis A, piston rod 5 reciprocates. The stroke of piston rod 5 can be varied by means of screw device 6 which adjusts the position of point G of link 4.
$1412$LG,PM$