Ratchet wheel 7 rotates about fixed axis A. Crank 1 rotates about fixed axis C and is connected by turning pair D to link 4 which slides in guide c of link 5. Link 5 turns about axis B. Link 4 is connected by turning pair E to link 6 which, in turn, is connected by turning pairs F to link 2 and to pawl 3 which engages ratchet wheel 7. Link 2 turns freely about axis A. When crank 1 rotates about axis C, link-gear mechanism CDB oscillates lever 2 about axis A and pawl 3 imparts intermittent clockwise motion to ratchet wheel 7. The angular velocity (and angle of rotation) of wheel 7 can be varied by changing the position of point B by means of screw b and nut a, and clamping them in the required position.
$1828$LR,ML$