Singer 72W19 - Page 21

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SEWING HOOKS
See Figs. 13 to 15
To Remove Either Hook from the Machine. Remove the
gib screw at the heel of the hook and move the gib aside to allow
the base of the bobbin case to be taken out, after which remove
the screw, from the center of the hook, shown in the cut. Tapping
the hook lightly from below on the bottom of its rim will force
it from its socket. Do
not pry it out, as prying may bend the
shank of the hook. In replacing the hook be sure that the prongs
of the shank properly enter the slot at the bottom of the socket,
otherwise the hook will be out of time.
To Remove Arm Shaft (d, see Fig. 2). Through the oil hole
near the needle bar loosen the set screw and remove the check
and position screws from the take-up cam; loosen piercer bar
driving cam screws, loosen the position screw at the back of the
arm which holds bushing (f), detach connections (c) from the
upper cranks, insert a light flexible rod through the large hole
in the arm over the cranks, drive out bushing (f) and draw out
the shaft.
To Remove Front Bushing (k). Loosen its position screw
at the back of the arm and after removing the needle bar, take-
up cam, etc., insert a rod through shaft bushing hole (back) and
drive out the front bushing.
When Replacing the Bushing see that the groove in the
bushing is in line for the position screw to enter, then drive the
bushing as far as it will go and tighten the screw. When setting
the take-up cam be sure to replace its position screw in the hole
nearest to the presser bar, when the screw holes are uppermost,
and turn it down firmly into the shaft, and replace the check
screw over it. The end pla}'^ of the upper shaft is taken up by
means of the screw in the end of the shaft at the balance wheel.
In Attaching the Balance Wheel to the shaft, the screw
farthest from the operator should enter the groove in the shaft,
when both screws are uppermost, otherwise the wheel will be
out of balance and cause the machine to shake.
AUXILIARY PIERCER T
To Set the Auxiliary Piercer. Loosen screw (P, see Fig. 16)
and set bracket (U) forward or backward as required. As the
From the library of: Superior Sewing Machine & Supply LLC