Abrams SC-1, Technical Manual

Page: 30 / 39

MAINTENANCE MANUAL
(item 3)
—
being
careful
not to lose the
star
nut spring (item
1)
—
and
remove,
successively, the pivot bolt, shadow bar washer
(item
6),
shadow bar (item
5),
and shadow bar bearing (item
4),
the solar plate (item
7),
and the date bar (item 8).
c.
The level
vial
(item
12)
is
removed by unscrewing two
screws (item
14)
inserting through the gimbal arm (item 10),
into
the
level
vinl casing.
Remove the level
vial
and casing
assembly and
the
level
vial casing washer (item 13).
d.
The
protractor
plate
is
secured to the gimbal arm and
bearing assembly (Item
11) by
two flat-head screws (item 15),
however,
the
protractor
plate
need
not
be
removed to dis
assemble the instrument.
e.
Unscrew
the
wing
nut (item
23)
from
the
hex-head bolt
(item
20)
which pivots and clamps the gimbal arm and bearing
assembly in the frame and trunnion
assembly (item 17).
Re
move
the bolt,
plain
washer (item 22), lock washer (item
21)
and slide the gimbal arm and bearing assembly out of
the
frame and
trunnion
assembly.
Unless the cap screw lock (item
16)
is damaged,
it
need
not
be
removed.
/. To disassemble
the
support assembly, unscrew the two
wing nuts (item
23)
from
the
hex-head bolts (item
20)
which
pivot and clamp
the
frnme and
trunnion
assembly
to
the sup
port.
Remove the bolts,
plain
washers (item
22)
lock washers
(item
21)
and fibre washers, and
lift
the
frame and
trunnion
assembly off the support (item 18).
Again, unless the cap
screw locks (item
16)
are damaged,
they
need
not
be removed
from
the
frame and trunnion assembly.
This
completes the
disassembly
of
the
Sun Compass Assembly.
2.
INSPECTION.
Make an inspection
of
the parts as outlined in Section V.
3.
REPAIR.
a.
Repair
of this instrument consists mainly of replacing any
damaged or broken part.
6.
If
the gnomon or sighting rods are bent,
carefully
bend
them
back
into
a
straight
rod.
If
the
luminous capsules are
broken, replnce
the
capsule and holder together
as a
unit,
by
unscrewing
the
holder from the rod and
installing
another
holder and capsule.
22