©1961
.,.. Am�rican Telephone and Telegraph Company
Printed in U. S. A.
P34.541
BELL SYSTEM PRACTICES
SECTION
Teletypewriter and Data Stations
lasue 1, October, 1961
AT&TCo Standard
28 TRANSMITTER-DISTRIBUTOR BASE
ANSWER-BACK MECHANISM
LUBRICATION
1. GENERAL
This section contains the specific lubrication procedures
for the answer-back mechanism of a 28 transmitter­
distributor base, if so equipped. The material herein, together
with the section entitled Teletypewriter Apparatus, Lubrication,
General Information and Routines, provides the complete lubri­
cation information for maintenance. The lubrication symbols
used herein are the same as those in the gene1·al section. How­
ever, the symbol 0 is used in this section to mean only one drop
of oil. Symbols, such as 02 and 04, are used herein to specify
that two or four drops respectively are to be applied at the
points indicated.
1.01
28 TRANSMITTER·
DISTRIBUTOR BASE
ANSWER­
P34.541
BACK
2. LUBRICATION DETAILS
2.01
Clutch-trip Magnet Mechanism
.._,.MATURE HtNGf
SAT
FELT Wl(lr.
0
tJt'>OtcS
-
E.t.:H END
!>ttiNG
SAT
FELT ClUJ
CLUTCH D!St�
CLUTCH LATCh lEVU:
CLUTCH TliP LEVU
0
2.02
SPRING
HOOKS - E.t!CH ENO
Contact Lever Assembly
0
I I
HOOKS
•
0
HOOt..S- £t,(H U"D (81
G
PIVOT POINTS (8)
G
PiVOT POiNTS (8)
(t>M fOLlO'•'•H
G
PIVOT POINTS (8)
DISTiiiWTQi ��OCK
0
HOOKS ·EACH fNO !B)
01
BEARING SUiFACES (!!)
.(A(H I: NO (8)
SPRING
OI)TRII!UTOR illQ(I(
SPitiNG
CONTACT LEVEll
C 0Mi'1H�:,tCN SP�ING
I t
2.03
Cam Shaft and Clutch Assembly
0<
INTERNAL MKHANISM
CLUTCH
C Ml ASSEMILY
CAM SHAFT
2.04
Driven and Driving Gears
rI
--�
---- --
GfM:HETI-1
________
�---------- G
I
G
PI',QT �lOLl" AhiO
ROLlU( ')IJRFACE
LOOP; ·tACH EN:.
FEfO PAWL sr�ING
GUIO!NG ')URi' ACt
GUIDE
LOOf>S - lACt1 H·IO
--··-- G
--'---
28 TRANSMITTER­
DISTRIBUTOR BASE
ANSWER-
GfAII.lHl't1
Nit:Nf lh'U S!"Ri�G
D!'l.!\'I::G GEAJt
2.05
Contact Assembly
INSUL...iC� SUF!FA(f
2.06
Ci ASSfMII.Y
CON: •••
Drive Plate and Feed Pawl Assembly
PI.QT
Fti:ll PAt.L
PIVOT SUIU..:..(t
MOUNTING SllA(I(fT
SHAFT AND STUD
DRIVE PLATf
....
2.07
..
•
Detent Lever
e;
�
2.08
.,
G
PIVOT HOLE
DETENT LEVER
G
ROllER
DETENT
LEVER
Baae Gears
G
GEAR: TEETH
BASE GEARS
{4GEAR:';)
Ol Olliff &AiiNGS (4)
(OIL EACH
S!Of
SASE BEARINGS
OF &EAII:INGS)
3. ASSOCIATED BELL SYSTEM PRACTICE
3.01
section.
The following Bell System Practice provides additional
information that may be required in connection with this
Subject
Alphabetical Index of 28-type Equipment, Bell System Practices, and Associated 28 ASR Station
Drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28 TRANSMITTER·
DISTRIBUTOR BASE
P34.541
ANSWER·
-o.�. •
BACK
Section
P34.001
e e
I I