AT&T Bell System Plant Adjustment Procedure page 6

SECTION 032-714-701
Roller-------..
Slide Plate--""""'"\
Pin-------~
Metal
washer----___,.~
1
Hard Rubber
Separator------~~-
Helical
Spring -------t?~--bllrq....J
Mounting
Strip-----~
r----Key Top
Screw
Fig. 1 0 - A6-type Key
(e) The distance between contact springs de-
signed to make contacts shall be
Min 0.016"
except at the contacts when the contacts are
open, and
Min 0.008"
when the contacts are closed.
Gauge by eye.
*2.09
Contact Pressure: Fig.
lO(B) -
There
shall be a pressure between all closed con-
tacts of
TEST READJUST
GRAMS GRAMS
MIN MIN
(a)
50 55
(b) 45 50
(c)
50 55
1/2 of split spring 25 30
(d)
30 35
Use the No. 68B gauge.
Note: Reference shall be made to the re-
quirement table for requirements for the
particular key.
Page 6
*2.10
Other Spring Pressures: Fig.
lO(C)-
The inside contact springs, which are
held apart by the hard rubber separators, shall
be tensioned against the shoulders of the rubber
separators so as
to
prevent the stud from coming
out of the hole in either spring when the inside
contacts are open.
Gauge by eye and feel.
*2.11
Contact Follow: Fig.
ll(A)
(a) There shall be a follow on all contacts
of
Test - Min 0.008"
Readjust - Min 0.010"
Gauge by eye.
(b) This requirement does not apply
to
the
inside contacts which are held apart by
hard rubber separators and the heavy inside
closed contact of make-before-break ( conti-
nuity) spring combinations.
..---Key Button
Hard
Rubber
Plunger
(A)
Plunger
Spring
Contact
Spring
0
Assembly
Clamping
0
Plate
Fig.
11-
818-type Key
*2.12
Contact Sequence
(a)
Normal Contact Sequence- Break-Make
Combinations: Fig. 12 (A) -Unless oth-
erwise specified, the normally closed contacts,
operated directly by a plunger spring of an
individual spring assembly, shall break before
the normally open contacts of the same spring