Model 219 Impulse Stepper; Stepper Contactor Arm Adjustment; Stepper Operating Arm Adjustment - Wurlitzer 3020 Service Instructions And Parts Catalog

Section Ill
Adjustments
Service Instructions
closed. With the armature held against the pole piece,
set the short contaCt blades of the normally open con-
tacts to such a position that they are deflected by the
long contact blades from .010 to .01;-inches. Nor-
mally closed contacts 5 and 6 should now be open and
upon releasing the armature they should be set so that
the short blade (contact 5) is deflected by the long
blade (contact 6) approximately .010 to .015-inches.
\Xfhen the relay is in a normally open posttton the
long switch blades extending through the armature
bakelite plate. should be slightly tensioned against the
upper side of the slot in the bakelite plate.
NOTE
Do not cbange the tension of the armature
sprit~g.
• • *
*
MODEL 219 IMPULSE STEPPER
STEPPER CONTACTOR ARM ADJUSTMENT
Adjust the stepper contactor arm by turning the
eccentric cam stop to position the contact on the step-
per arm long blade to be exactly on the first contact
of the segment disc. (See Figure 23.) The stepper
arm long blade should not have more than 14 grams
and not less than 10 grams pressure. The short blade
of the contactor arm should not have more than 18
grams and not less than 14 grams pressure.
STEPPER OPERATING ARM ADJUSTMENT
NOTE
Do not attempt to adjust the stepper operating arm
without first checking the adjustment o_f the stepper
contactor arm as mentioned above.
When properly adjusted, the eccentric cam stops A
and B, shown in Figure 24, regulate the stroke of the
operating arm to prevent stepping more than one step
per impulse. Adjust cam stop A to permit the ratchet
18
STEPPER CONTACTOR ARM
ECCENTRIC
CAM STOP
SHORT
CONTACTOR
ARM
figure 23 -Stepper Contactor Arm Adjustment
pawl to engage the proper first tooth on the quadrant
gear. Adjust cam stop B to limit the stroke of the
operating arm, and ratchet pawl, so that the contac-
tor arm advances only one step through the action of
the quadrant gear. When the operating arm is held
against the cam stop B, there should be 1/64-inch
clearance between the point of the quadrant gear tooth
and the point of the ratchet holding pawl.
STEPPER SWITCH ADJUSTMENT
The blades of the stepper switch are normally open.
(See Figure 25.) The long blade should at all times
bear against the fibre insulator on the operattng arm.
When the switch is open, the short blade should bear
against · the center locating blade. At the time the
ratchet pawl begins to engage the tooth in the quad-
rant gear, the Jong switch blade should begin to de-
flect the short blade. It is very important that a good
wiping action be provided to prevent burning or pit-
ting of the points.
OPERATING ARM
WITH OPERATING ARM AGAINST CAM STOP B, THERE
SHOULD BE 1/64-INCH CLEARANCE BETWEEN POINT ON
QUADI(ANT GEAR TOOTH AND POINT OF RATCHET
HOLDING PAWL.
figure 24 -Stepper Operating Arm Adjustment