Reader Check Lights - IBM 1402 Reference Manual

CONDITION A
CORRECT OPERATION
CONDITION B CONDITION C
CLUTCH FAILED TO TRIP CLUTCH FAILED TO LATCH
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SETUP
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+EXT ON 1401 READ FEED TRIG, PIN "E"
TIME: 5 MS/DIV (APPROXIMATELy)
VERTICAL: 10 VOLTS/DIVISION
Figure 6-3. Clutch Failure Patterns
METHOD B
This method pertains to the Model 3 and all models
with Early Read special feature.
1. On machines with Early Read Feature, the read
clutch sync switch must be turned on. Set CE
panel cam selector switch to CLC 1 or 2.
2. With this set-up on the 1402, the dynamic timer
should always show the same timing of the CLC
impulse. If the 1402 clutch fails to engage when
it is tripped, the CLC impulse will move to
another early read latching time.
3. ''''hen reader clutch problems exist, they may be
the result of mechanical problems in the reader
clutch. Typical troubles are:
a. Breakage of drive arms or dog/detent pivot
studs on the reader clutch assembly causing
reading failures or reader stops.
b. Dirt causing slow response when the clutch
is tripped. Cleaning and lubricating the reader
clutch once every 12 weeks is recommended
for single shift operations. Refer to scheduled
maintenance chart in this manual. The addi-
tion of additional .010/1 shim, 602033, between
the intermediate arm and the drive arm will
make the clutch less prone to contamination.
c. Eccentric screw adjustment causing failure of
clutch to latch or unlatch. This is caused by
eccentric screw adjustment if insufficient clear-
ance is not maintained between the keeper
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OR EXTRANEOUS CLUTCH CYCLE
NOTE: NO SYNC PULSE
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NOTE: A DISPLAY OF SYNC
B DISPLA Y OF READ FEED PICK RLCB
MAKE 120· BREAK 170·
RLCB 3 USED WiD SUFFIX A THRU T
RLCB 7 USED WiD AFTER U
latch, drive arm, and latch when the clutch
is latched up.
d. Insufficient clearance between the detent and
ratchet when the dog is engaged. The detent
may not engage the ratchet wheel; whipping
will result. Maintain a .002/1 clearance.
e. Incorrect armature spring tension or keeper
latch spring tension causing slow clutch trip
response.
f. Clutch magnet RCCB 5 making late causing
clutch failure due to lack of time to engage.
Set the RCCB on early limit of make tolerance.
g. Armature wear (notch) opposite upper arm
of yoke causing the .020-.022 yoke to armature
clearance to change, and the .002/1 -.005/1 arma-
ture-to-coil clearance to change. These two
clearances must be maintained. It is difficult
to observe the notch wear; therefore, check the
adjustments periodically.
h. Loose reader clutch coil causing reader clutch
unlatching failures.
Reader Check Lights
CAUSES
1. Card skewing between read stations: Inspect the
feed area for uneven feed roll pressure. Pressure
should measure at least 6 pounds on a strip of
IBM
card when drawn through any single set of
feed rolls.
6-3