Pin wheel 1 rotates about fixed axis A and has pins a. When wheel 1 rotates clockwise, pins a engage bevelled face b of pawl 2 and bevelled face d of pawl 3, turning the pawls about fixed axes B and D. Reverse rotation of wheel 1 is prevented because pins a run against faces c and e of pawls 2 and 3.
$2616$PG,D$