Reader Clutch - IBM 1402 Reference Manual

2. Loosen idler pulley. Install belt and tighten with
idler pulley.
3. Loosen picker knife camshaft drive pulley.
4. Trip clutch by hand and turn index to 216
0
for
three-group brushes, or 212
0
for two-group
brushes. Place card against first feed rolls, and
manually turn picker camshaft in normal machine
direction until feed knives touch card. Tighten
pulley locking screws. This is a reference point.
Check brush timing with timer index, .and shaft
picker camshaft to get proper timing.
NOTE: Any change in picker knife timing will
directly affect RLCBs and solar CB.
5. After brushes are in time, reinstall solar cell unit.
a. Remount solar cell mounting plate Hush
against shoulder of three studs and tighten
three set screws, located in mounting plate.
b. Reinstall disk, and slightly tighten mounting·
screw. Be sure disk is located in center of solar
cell mounting block. If care has been taken in
removing and reinstalling cell unit and'disk,
it will be located in same place (in reference
to cell mounting block) as it was originally.
See Figure 3-2. .
6. To retime solar cell, refer to Electrical Compon-
ents, Solar Cell CB, Timing Procedure.
7.
At this point, it may be advisable to time
RLCB~s
to ensure proper tolerance.
Reader Clutch
Adjustments of the reader clutch are the
sam~on
all
models. Modell, with Early Read special fea-
ture, uses a six.-tooth ratchet clutch. The Early Read
feature is standard on the Model 3, 4, 5, and 6. A
two-tooth ratchet is used (standard) on other models.
Caution: Be sure the clutch is latched up when you
finish working on it. Nipping and possible machine
damage will result if the clutch is not latched.
The reader clutch can be adjusted either in machine
or when clutch drive unit is removed. Steps 1-4 should
CELL MOUNTING
BLOCK
'---tt-........ _ - - CENTERED
IN SLOT
Figure 3-2. Disk Centering
3-2 (4/67)
be performed only when a new clutch assembly is in-
stalled, or when complete adjustment is to be made
to center plate assembly and clutch magnet assembly.
When a complete adjustment is to be made, the read
clutch locating plate gage 610147 must be used.
NOTE: Use of this gage will ensure a parallel con-
dition, at latch-up time, between drive arm latch sur-
face and latch. If adjustments are to be made only to
the armature, latch, and magnet, begin at Step 5.
ADJUSTMENTS
1. Remove clutch pulley assembly. See
Clutch Pul-
ley Assembly, Removal.
2. Remove latch keeper and latch from center plate
assembly. See Figure 3-3.
3. Position locating gage on center plate assem-
bly studs and clutch pulley shaft with posi-
tioning block loose. See Figure 3-4. Secure posi-
tioning block against bottom of center plate as-
sembly as far to left as possible (Figure 3-3). Re-
move gage.
4. Reinstall latch keeper, spring, and latch. Follow
Clutch Pulley Assembly, Installation for re-
assembly of clutch p.~.liIey assembly. See Figure
3-3.
5. Adjust armature pivot bracket to maintain .002"
to .005" clearance between armature and core. See
Figure
3-~.
.
6. There should:- be .020" to .022" Clearance be-
tween armature and yoke with latch
agai~st
back-
stop. See Figure 3-3B ..
7. Hold armature attracted, and remove slack from
linkage by pushing latch toward drive arm (Fig-
ure 3-3B). Position center plate assembly on posi-
tioning block to get slight drag on .OOS" feeler
gage between latch and clutch drive arm. Tighten
center plate assembly mounting screws. There
should be at least 75% of latch in contact with
driv.e arm assembly in latched condition.
NOTE: Be sure to keep center plate against
positioning block.
S. Loosen positioning block mounting screws and
position block as far right (ear of locating block
against plate) as possible. Lock mounting screws.
9. Adjust center eccentric keeper stop stud to obtain
.000" to .020" between clutch drive arm and latch
keeper at latch time. See Figure 3-3C.
10. Check for
ro2"
clearance between step on ratchet
and detent (backlash) with clutch engaged. If
there is more than .002" clearance, install a longer
detent.
NOTE: Seven new detents, 609737 through
609743, are available in .002" progressions. These
detents are etched 1 thtough 7.