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iNSTRUCTIONS FOR MECHANICS (C ontinued)
UPPER MAIN SI-LA[T
In a high speed machine, the alignment of the take-up mechanism is extremely
important and is controlled by the left and right position of the upper main shaft.
Should the main shaft position be altered, it is imperative that the take-up alignment
be checked before operating.
TO CHECK FOR ALIGNMENT
1,
Remove the presser bar spring and regulator
screw
i
r
i. i
i—-------
U
J
2,
Rotate the handwheel so that the needle bar is
EE
t
;
1
E E;:s sure, move the
-—----
-'.--------
take-up lever tothe take-up lever boss. There
should be a small amount of interference
t
,
between the lever and the boss,
With light
B
)
\
outward
finger
pressure,
move the lever
r /
!—
across
the
boss
face,
There
should
be
clearance between the boss face and lever,
Fig, 23
These two tests in effect are checking the
lateral play of the take-up lever and provides
for operation of the take-up inthe center of the lateral play, Now, line up the take-up
lever hole with the hole in the lever boss,
Insert the oil wick about 1/2 inch in the
bore of the take-up lever. With the oil wick groove up, insert the take-up lever pin
in the lever, making sure the wick is in the groove and press the pin into its hole in
the arm.
There should be no end play in the take-up lever after the set screw is
securely tightened,
Should the alignment test show the main
shaft is out of position, the upper sprocket and
handwheel should be loosened and the shaft
moved left or right as the conditions indicate.
Re-tighten sprocket and handwheel so that there
—
is no end play in the upper main shaft and repeat
the alignment check.
HAND WHEEL
I
The handwheel is
constructed so as to
/
minimize noise and is therefore isolated from
the pulley by shock mounts.
If for any reason
/
the handwheel is disassembled, the following
steps should be used for re-assembly.
Fig. 24
1.
Using the upper main shaft as a mandrel, assemble the pulley thrust face down
sothat at least 1 1/2 inches of the shaft protrudes above it. Tighten the two set
screws.
2.
Place the rubber isolator ring on the pulley face and align holes.
3.
Carefully slide handwhcel down the shaft to contact the isolator and align the
three holes.
21
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