Link 2 of four-bar linkage BCDE has pin (roll) a at point A. This roll engages slots c of Geneva wheel 3. When crank 1 rotates about fixed axis B, roll a of link 2 drives Geneva wheel 3 intermittently with dwells. The wheel dwell corresponds to portion y-y of the path of roll a. Concentric surface b of crank 1 slides along concave surfaces d of Geneva wheel 3 to prevent unintentional rotation of the wheel during its dwell periods. In one full revolution of crank 1, Geneva wheel 3 is indexed through 22.5°.
$1754$GL,D$