Connecting rods 5 and 6 are connected by turning pairs B and D to crank 1, turning about fixed axis A, and by turning pairs C and F to rocker arms 3 and 4 which turn about fixed axes E and G. Connecting rod 8 is connected byker turning pairs M and K to rocker arm 4 and to rocker arm 7 which turns about fixed axis L. Link 9 is connected by turning pairs H and N to rocker arm 7 and to link 2 which, in turn, is connected by turning pair Q to rocker arm 3. When crank 1 turns about axis A, serrated member a, mounted on link 2, has a complex motion in which it grips and advances the cloth being sewn.
$890$LW,FD$