Removal And Replacement Of Principal Assemblies; To Remove The Sewing Hook - Singer 491D Service Manual

Machines of Class 491D are made with extreme precision in machining and
assembly, and the "Superfinish" process provides microscopically smooth bearing
surfaces. Therefore, special care should be taken not to permit any misalign-
ment of parts or to cause any scratches or nicks on the bearing surfaces by
careless assembly or handling of parts. Any such damage might render the ma-
chine incapable of the long, trouble-free service for which it is designed.
Q
S
R
Fig. 14
Remove the needle, slide plate, throat plate and bobbin case. Remove the
screw R. Fig. 14 and the bobbin case holder position bracket S, Fig. 14. Loosen
the two set screws L, Fig. 14 in the hub of the hook and turn the machine pulley
over toward the operator until the feed bar Q is raised to its highest point.
Turn the sewing hook until the thread guard U, is at the bottom, as shown
in Fig. 15. Turn the bobbin case holder V, Fig. 15 until the notch W is also
near the bottom, as shown in Figs. 15 and 16. The sewing hook can then be re-
moved from the hook shaft.
INSTRUCTIONS
FOR
REMOVAL AND REPLACEMENT
OF
PRINCIPAL ASSEMBLIES
CAUTION TO MECHANICS

TO REMOVE THE SEWING HOOK

V
L
W
- 8 -
X
NO. 143042
U
Fig. 15