Cylinder cam 1 rotates about fixed axis A and has helical cam slot a which periodically engages a pin b of pin wheel 2. Pin wheel 2 rotates about fixed axis B. When driving cam 1 rotates continuously, driven pin wheel 2 rotates intermittently with short dwells, during which it is locked against unintentional rotation by parallel faces f of cam 1 which fit between adjacent pins b.
$2620$PG,D$