Bell System Practices Plant Series Adjustments page 6

SECTION 573-115-700
standard format. Since this is a general revi­
sion, marginal arrows are omitted.
1. 02 The adjustments in this section are di-
vided into basic units, variable features,
and earlier design mechanisms.
consist of the friction feed and
typing units; the adjustments
into major mechanisms most of which are com­
mon to both units. All other mechanisms which
are of an optional nature to create variations of
the 28 typing unit, appear under variable fea­
tures. When applicable, earlier design mecha­
nisms for the basic units and variable features
are cross referenced in their adjustment text.
Note: Remove power from unit before making
adjustments.
1. 03 The adjustments for the basic units are
arranged in a
followed if a complete readjustment were under­
taken. After an adjustment has been completed,
be sure to tighten any nuts or screws that may
have been loosened to facilitate the adjustment.
If a part that is mounted on shims is to be re­
moved, the number of shims used at each mount­
ing screw should be noted so that the same shim
pile up can be replaced when the part is re­
mounted.
1. 04 The spring tensions given in this section
are indicated
checked with proper spring scales in the position
indicated. The adjusting illustrations, in addition
to indicating the adjusting tolerances, positions
of moving parts, and spring tensions, also show
the angle at which the scale should be applied
when measuring spring tensions.
1. 05 Tools and spring scales required to per­
form the adjustments are not supplied as
part of the equipment but are listed separately
in Teletype Bulletin 1124B.
1. 06 References made to left or right, up or
down, and front
typing unit in its normal operating position as
viewed by the operator facing the unit.
1. 07 Where instructions call for the removal of
parts or subassemblies, refer to appro­
priate section, covering Disassembly and
assembly.
UNMOUNTED POSIT IONS OF TYPING UNIT
1. 08
The typing unit may be safely placed in
any one of three positions for servicing:
Page 6
The basic units
sprocket feed
are sub- divided
sequence that would be
values and should be
or rear apply to the
Re­
(1)
In an upright position, and resting on all
four feet.
(2) Tilted backward, and resting on the two
rear feet and rear points of side frames.
(3) Bottom upwards,
upper points on each side frame.
In addition, the typing unit may be
either end by using the TP159358 modification
kit (not supplied with the unit).
OPERATING CONDITIONS OF CLUTCHES
1. 09 When a requirement calls for a clutch to
be disengaged, the clutch shoe lever must
be fully latched so that the clutch shoes are dis­
engaged from the clutch drum.
latched the trip lever must engage the clutch
shoe lever, and the clutch disc must rotate far
enough to permit the latch lever to fall into the
notch on the clutch disc.
tion is illustrated in the upper figure of Par.
2. 21. When engaged, the clutch shoe lever is
unlatched and the clutch shoes are wedged against
the clutch drum.
Note: When rotating the
typing unit by hand, the clutches do not fully
disengage upon reaching their stop positions.
In order to relieve the drag on the clutches
and permit the main shaft to rotate freely,
apply pressure to the stop lug on each clutch
disc with a screwdriver until each latch lever
falls into its notch on its clutch disc.
each internal expansion clutch becomes fully
disengaged. This procedure should be fol­
lowed before placing the typing unit on the
base and switching on the power.
MANUAL SELECTION OF
FUNCTIONS
1. 10 To manually operate the typing unit while
removed from the keyboard or base, hold
the selector magnet armature (Par. 2. 01) against
the pole pieces with an armature clip.
the main shaft in a counterclockwise direction
(handwheel listed in Bulletin 1124B) to bring all
clutches to their disengaged position.
Note: The anmature clip is attached to the
armature by carefully
formed end of the clip over the top of the
armature and between the pole pieces, and
hooking the extruded projection under the
edge of the armature.
and resting on two
placed on
To become fully
The disengaged condi­
main shaft of the
Thus
CHARACTERS OR
Rotate
inserting the flat
The top end of the clip
"'