Face cam 1 rotates about fixed axis A and has two profiled grooves, a and b. Followers 4 and 5 turn about fixed axes B and C and carry rollers 2 and 3 which roll and slide along grooves a and b. Link 8 is connected by turning pairs E and D to follower 4 and to lever 9 which turns about fixed axis F. Links 4 and 9 have notches e and d for setting and clamping shackles 10 and 16. Link 11 is connected by turning pairs K and N to follower 5 and to link 12 which turns about fixed axis M and carries rigidly attached pawl 7. Pawl 7 periodically engages ratchet wheel 13 which rotates freely about axis F. Pawl 6 turns about axis T and is engaged to and disengaged from wheel 13 by links 14 and 15. When cam 1 rotates, pawl 6 rotates wheel 13 intermittently with dwells whose length can be varied by adjusting shackles 10 and 16 (at the ends of link 8) along links 4 and 9, and clamping them in the required positions. During the dwells, pawl 6 is raised by links 5, 11, 12, 14 and 15, and pawl 7 is engaged to wheel 13 to prevent its unintentional rotation.
$3350$CR,LL$