A clockwise torque about fixed axis B is applied to ratchet (escape) wheel 3 by weight Q. Balance (flywheel) 4 is oscillated about fixed axis D by the action of spiral hairspring 1 and has pin a sliding in fork b of anchor 2. This oscillates anchor 2 about fixed axis A and its pallets allow intermittent rotation of escape wheel 3.
$2749$RG,G$