Crank 1 of four-bar linkage ABCD rotates about fixed axis A and is connected by turning pair E to slider 4 which moves along slot d of link 5. Link 5 is connected by turning pairs F and G to links 6 and 7. Link 6 is connected by turning pair K to link 3 which turns about fixed axis M and is fixed by screw b in one of the positions in circular groove c. Link 7 turns about fixed axis N and is connected by turning pair H to link 2. Slider 8 moves along slot f of link 2 and is connected by turning pair L to rocker arm 9 of four-bar linkage ABCD. Rocker arm 9 turns about fixed axis D. When crank 1 rotates about axis A, serrated member a, mounted on link 2, has a complex motion in which it grips and advances the cloth being sewn. Link 3 regulates the stitch length.
$1466$LG,FD$