Link 1 reciprocates in fixed guides a-a. Pawls 3 and 4 turn about axes C and B of link 1, alternately engaging teeth d of ratchet wheel 2 which rotates about fixed axis A. Pawls 3 and 4 are held in engagement by springs b. When link 1 reciprocates, it slides with its slot f on the hub of wheel 2, and pawls 3 and 4 rotate the wheel intermittently counterclockwise. The pawls prevent wheel rotation in the reverse direction. Members e lock wheel 2 at the instants it is being engaged and disengaged by pawls 3 and 4.
$2730$RG,ML$