Ratchet wheel 2 and lever 1 turn independently of each other about fixed axis A. Lever 1 is connected by turning pairs B and C to pawls 3 and 4 which are held against ratchet wheel 2 by springs 5. Pawl 6 locks ratchet wheel 2 against reverse rotation at the moment when pawls 3 and 4 are out of engagement with the teeth of wheel 2.
$1797$LR,4L$