Pfaff 4874 Service Manual page 40

CHAIN LOOPER : ANGULAR POSITION - CLEARANCE - ORBITAL
TIMING - CLEARANCE OF CHAIN NEEDLES GUARD 12a
L2
1.5~1.8mm
L0
e
d
a
c
Fig.2
Fig.1
L0 L2
Motion
Fig.3
0~0.05mm
1.0mm
e
Fig.4 Fig.5