Singer 620 - Page 21

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NEEDLE-BAR DRIVING ARM
TENSION NEEDLE BAR BALL
ARM DRIVING ARM PIVOT
CENTER LINE
GROOVE
NEEDLE BAR DRIVING ARM
Removal and Replacement
Remove arm top cover and face plate.
Remove cam-selector-arm shaft as instructed on
page 15.
Remove needle-bar vibrating bracket.
Lift needle-bar driving arm from machine.
Replace needle-bar driving arm in arm of machine
so that ball pivot rides in socket provided for it in
pattern selector, as shown.
CAUTION; Make certain that tension arm is in cor¬
rect position in relation to driving arm,
as shown.
Replace cam-selector-arm shaft as instructed on
page 15.
Replace needle-bar vibrating bracket.
Adjustments
Centralizing Needle-3ar Driving-Arm
Get oignt-amDiiruae stOD-piares as instrucrea an
cage 18 .
Get bight lever at No. 3 position.
When bight lever is set at No. 3 position, the
center line of needle-bar driving arm should coincide
with a point midway between selector-arm followers.
Loosen bight-lever clamping-screw.
Push lever bracket toward left as far as possible.
Align center line groove of bight lever with No. 1
position, as shown.
Tighten bight-lever clamping-screw.
Move bight lever as far as possible to the right.
Center line groove should now be in line with No. 5
position, as shown.
If center line groove of bight lever is not in line
with No. 5 position, loosen bight-lever screw and,
while holding bracket to extreme right, move lever
1/2 the distance that it is out of line. Then tighten
bight-lever clamping-screw. Lever will now be an
equal distance from center position No. 3 when set
at No. 1 and No. 5 positions.
Replace arm top cover and face plate.
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