Model
2000
Stepper
(2)
Contact pressure of the common con-
tacts (Items
1
and 5) against their respective com-
mutators should be minimum 20
grams.
Any change
in setting should be made with the contact plate re-
moved. The arms may then
be
shaped to provide the
requiredpressure.
The common contact that
is
mount-
ed in the contact plate assembly consists of a con-
tact blade and a bracer blade. The bracer blade
should be set so that its tip clears the contact blade
by
.025".
g.
Release Relay Adjusments. (Fig.
38)
(1) The return spring tension (Item 10)
should be set to provide approximately 125 grams
upward pressure as measured at the armature
ex-
tension (Item 1). Without aid from the holding dog
torsion spring, the 125 grams should just move the
armaturefrom its stop. The tension must be sufficient
to raise the holdingdog from any of the ratchet teeth.
(2) When actuated, the tip of the armature
extension must clear the holding dog
by
minimum
.010" at its closest
polnt
of operation.
(3)
Vertical adjustment of the release relay
may be made
by
loosening the two screws (Item
9).
The vertical adjustment should raise holding dog to a
point
that
will
clear the ratchet teeth .01OV minimum
when the relay
is
released and the ratchet wheel is
retracting to zero
position.
h. Relays.
(1) Normally open contacts should be dress-
ed to provide a minimum gap of
.005" and minimum
,
contact overtravel of .01OW.
(2) Normally closed contacts should be
dressed to provide
a
minimum gap of'.015", when
open, and a minimum contact overtravel of
.006"
when closed.
Complete instructions for installations of Wall
Boxes
is
furnished with each wall box.
5.
STEPPER MAINTENANCE
a.
Lubricateall moving
partswtth a light appli-
cation of
S.A.E.
No. 10 oil.
b.
The contact discs should be sparingly lubri-
cated with white petroleum jelly, using a clean, lint
free, cloth which has been impregnatedwith the lubri-
cant.
All excess lubricant must be removed.
c.
All
switch and relay contacts should
be
kept
cleanwith carbon tetrachloride and
a
clean
dry
cloth.
,-
Burnishing of contacts with a strip of heavybond paper
is
recommended. Abrasives should be avoided.
Page
28
Issue 1
Model
2000
Stepper
The
Rudolph Wurlitzer Co.
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