Adjusting The Needle Guard - JUKI MF-7800D Series Engineer's Manual

(11) Adjusting the needle guard

1. Standard position of the rear needle guard
(1) Height of the rear needle guard
It is the standard that the clearance provided
between crest line A of rear needle guard
the top end of right needle is 1.5 mm to 2 mm when
top end of the looper
right position to the center of right needle.
(2) Lateral position of the rear needle guard.
It is the standard that the lateral position of rear
needle guard is the position where the rear needle
guard receives the needle in the range of B.
(3) Adjusting the longitudinal position of the rear needle
guard.
It is the standard that when top end of the looper
comes from the extreme right position to the center
of right needle, the clearance provided between the
right needle and top end of the looper
mm, when top end of the looper
center of middle needle, the clearance provided
between the middle needle and top end of the looper
is 0 to 0.05 mm, and the pressing amount of the
top end of needle touches the rear needle guard.
(4) Loosen two setscrews
guard.
It is the standard position where setscrew
rotation) aligns with engraved marker dot
Standard Adjustment
and
comes from the extreme
is 0 to 0.05
comes to the
in the rear needle guard cam and perform the adjustment of the rear needle
in the rear needle guard cam (screw No. 1 in the direction of
on the looper driving shaft.
– 28 –
A
B
Advanced
Retarded