Double crank 3 rotates about fixed axis Connecting rod 4 is connected by turning pairs B and P to crank 3 and slider 5 which is driven by piston a of the steam engine. Reciprocation is transmitted to slide-valve 2 through a complex system of levers. Link 7 is connected by turning pair N to connecting rod 8 of slide valve 2. Link 7 is actuated from one end by crank 3 through connecting rod 6, and from the other end by the same crank but through links 11, 12, 13, 14, 10 and 9. Links 12 and 9 turn about fixed axes 02 and 06, and link 14 about fixed axis 0₄ of lever 1 which turns about fixed axis 0₃. Lever 1 can be set at various positions, thereby changing the position of fixed axis 0₄ of revolution of lever 14. This also changes the path of point N of link 7 and, consequently, the motion of slide valve 2. Lever 1 is shown in its extreme position for which the stroke of slide valve 2 is the maximum.
$1659$SC,VG$