Tally 424 User manual

TAPE
READER
Revis ed 4-1-62
MANUAL
MODEL 424
This publication reproduced
with the permission of
TALLY REGISTER CORPORATION
1310 Mercer Street
Seattle 9, Washington
D - 1066

.··.
Figure
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LIST OF ILLUSTRATIONS
Model 424C Console Reader .
6" and 10" Tape Reels ....
Title
Model 424PF with Fanfold Tape Handling .
Model 424PR with 6" Reels ..... .
Model 424PR with 6" Reels, Plan View
Capstan Drive, Exploded View .. . .
Star Wheel Reading Perforated Tape
Timin g Diagram
Wiring Diagram
Spark Suppressi on Waveforms .
Standard Tape Dimensions.
Lubrication Chart . . . . .
Tape Read Head, Exploded View .
Checking Contact Pressll!'e with a Gram Gage
Correct Positioning ior Star Wheels .
Escapement Adjustments
Bad Tape Splice . . . . .
Bi-directi o nal Tap e Splice .
End-of-Tape Switch Schematic.
End-of-Tape Switch Adjustments.
Capstan Commutat .) r
Commutator Timing Diagram
Model 424P Tape Rea der , Parts List
Model 424C Tape Reader , Parts List
Capstan Drive, Parts List ... . . . "
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Figure
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LIST OF ILLUSTRATIONS (Continued)
Tape Read Head, Parts List . . .
Reel Drive Mechanism, Parts List
End-of-Tape Switch, Parts List .
Commutator Unit, Parts List . .
Title
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30
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33
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:. ''
..'
Figure 1. Model 424C Console Reader
/' / "'"
((
7.
-- ...,\
Figure 2. 6" and 10" Tape Reels
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Figure 3. Model 424PF Reader With Fanfold Tape Handling.
Figure 4. Model 424 PR Reader With 6" Tape Reels
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REEL DRIVE BELT L.H. /
-CABLE CONNECTOR r DRIVE MOTOR
, F USE MOTOR CHASSIS
C APACITOR
\ -CAPSTAN
I l)RIVE BELT
1-REEL DRIVE
BELT R.H.
REEL DR I VE --
MECHANl SM LH .
i...
,--·-
0 ~· ~ L
' .....1-.
I
1-4 :
I~ I ... .. -·---r 1_ I ~ I I
'--4 ... , "":------'-...J... ~ _.J : I
l
·, ; ., I I ·1 I
\ j I !.r--------- - --'J . ri
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__ l ___ J I
---·-- -- - · ·- -- ---,.----- ------ -"!--"t:===='i"I- --- ----,-,-------~
~ r"-- - ---- -
'· v·· ·- ---- .'
__ ,r -- =, --·- ! i I -
~~-~"""""~==========~===--...,1 -:- ·- ---:_ ____ ...- __ ....... """" r -===:=:!!!~~==~~====~====~'=== ====
/ \ \
LIFT LEVER \- TAPE
TAPE TENSION ARM ~
REEL
READ HEAD ASSEMBLY ~
Figure 5. Model 424PR Reader With 6" Reels, Plan View
R.H.

Section
1
2
3
4
5
6
7
8
TABLE OF CONTENTS
Title
INTRODUCTION . . . . . . . . .
1.1 General Specifications .
1.2 Description . . .
1.3 Input Requirements . .
1.4 Outputs . . . . . . . .
1.5 Tape Handling . . . . .
1.6 Environmental Conditions
MECHANICAL OPERATION ....
2.1 Motor and Capstan Drive
2.2 Tape Read Head ..
ELECTRICAL OPERATION .
3.1 Escapement Operation .
3.2 Switching Action . . . .
3.3 Timing . . . .....
3.4 Cycle Length Limitations
3.5 Terminations . . .
3 .6 Spark Suppression
3. 7 Contact Ratings
INSTRUCTIONS FOR USE .
4.1 Paper Tape Standards and Channel Identification .
4.2 Threading Tape
MAINTENANCE . . . • . .
5.1 Lubrication .....
5.2 Read Head Service .
5.3 Drive System Parts Replacement
TAPE SPLICING . . . . . . . . . . .
SPECIAL ACCESSORY EQUIPMENT
7.1 End-of-Tape Sensing Switch .
7.2 Capstan Shaft Commutator . .
PARTS ORDERING AND PARTS LISTS.
1
2
2
3 ·
3 '
3
3 :
3
5
5
5
6
6
6
6
6
9
9
9
9
10
10
10
14
15
17
17
18
21
TALLY
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7"YP/CA?L. ~PAt:"/~ -
...VOh'-.-A:"'C:-V- Z:~
,,.,v,,.,,r,.,,,.L' .A:::>O
A
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A
/ Jt'.010~ /...YC...,.
~ e . .:)0$ /.M::N
~..c~D7 ,.~...,
,.0 ,.e -~1,,,~
Figure 11. Standard Tape Dimensions
5.0 MAINTENANCE
5.1 Lubrication (See Figure 12)
After eve ry 500 hours of operation, lubricate the following:
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s
~
!1
2
(a) Escapement Clutch Assemblies. Lubricate both sides of each escapement clutch
assembly between the friction washers and the spur gear with silicone oil, 350 centipoises.
(b) Shaft Bearings. Lubricate shaft and idler gear bearings, using rust and oxidation
i nhib ited oil, SAE 20 grade. If the reader is equipped with tape reeling equipment, the reel drive
mechanism bearings should also be lubricated with the same oil.
(c) Escapement Assembly. Clean, and then lubricate each escapement armature ful-
crum with a light film of Tally pivot grease A. The adjacent armature pole face must be wiped
clean of all lubricant.
(d) Drive Motor. Lubricate drive motor bearings using rust and oxidation inhibited oil,
SAE 20 grade .
5.2 Read Head Service
5.2.1 Trouble-Shooting Reading Errors
If erratic readings are detected, examine the contacts for dirt or pitting. If dirty,
clean as outlined in Section 5.2.2. If pitted, they should be replaced and adjusted per Section
5.2.3. Check the star wheels and star wheel levers for free movement, and clean if neces sary.
Check switch timing and contact pressure per Section 5.2.3.
5.2.2 Cleaning Contacts
Access to the read head contacts may be gained by removing one screw on the
front of the read head cover and withdrawing the cover away from the front panel. If the con-
tacts are dirty or corroded, they should be cleaned with methyl ethyl ketone. Use a fine brush
or pipe cleaner as the applicator, and dry with compressed air. Use caution not to bend the
small movable contact wires with the brush or air blast.
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POINT NO .'
LUBRICANT l
"""? i)
MINERAL OILI S
AE
20 !
2)
TALLY
GREASE "A"
!
· ~
SILICONE O
IL I 3!50 cs :
Fi gure 12. Lu br ic a tio n Chart
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P age 11

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TALLY
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-.i
Keep the star wheels and star wheel levers free of lint and hair. They must have
free movement to read tape without error. II lever movement becomes sticky, clean pivot bear-
ings with methyl ethyl ketone and relubricate with SAE 20 oil.
5.2.3 Read Head and Contact Adjustments (See Figure 13)
Reading errors may be caused by incorrect adjustment of the read head assembly.
The first step in adjustment is to verify that each of the eight star wheel levers (36) are free to
move in a vertical direction without drag on the adjacent levers .
The star wheels (37) must also be centered over the capsta n. The star wheel
position with respect to the center of the capstan may be adjusted horizontally by loosening the ·
pivot bushing (30) and moving the read head adjusting eccentric (29). ·
The movable contact wires (34) must be free to move up and down in the gap be-
tween the fixed contacts (31). Improper alignment may be corrected by carefully bending the :
movable contact wire at its base.
The fixed contact gap opening must be between .025 and .030 inche.s wide . Exces-
sive gap may be corrected by bending the normally open (lower) contact.
Contact pressure should be 14-22 grams per pair of wires when in either the
N/O or N/C position. Lower contact (N/O) pressure may be checked by applying upward force
under the wires adjacent to the fixed co ntact , with a gram gage and wire tool as shown in Figure
14a. Observe the force required to lift the wires when switch contact is broken on the oscillo-
scope. Lower contact pressure is increased by moving the fixed con tact bl ock upward.
(a}
(b)
Figure 14. Checking Conta ct Pressure with a Gram Gage:
{a) checking lower contact pressure;
{b) checking upper contact pressure
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Insert no-hole tape in the read head, and apply down force on the wires with the
gram gage and wire tool to check upper contact pressure as shown in Figure 14b. Upper contact
pressure is increased by lowering the read head through use of the depth adjusting screw (28)
Figure 13, and the lever eccentric (25).
After contact pressure has been adjusted , switch timing should be verified with an
oscilloscope per the timing diagram, Figure 8. Check the switch timing of 18 channel against
15 channel. If they do not coincide within the 7-14 millisecond range, slightly rotate the fixed
contact block.
When alternate hole, no-hole tape is positioned so the star wheel is sensing a
"no-hole" condition, the two points in contact with the paper must be equally spaced from the
edges of the adjacent holes as shown in Figure 15.
Figure 15. Correct Positioning for Star Wheels on Alternate
Hole- No- Hole Tape
If the star wheel is not symmetrically located between tape holes, contact
switching will occur early or late depending on direction of tape movement. Contact switching
should be checked on an oscilloscope by stepping the tape first forward and then in the reverse
direction. If the switching in both directions is not within the 7 7 14 millisecond zone, loosen
the recessed head clamp screw and turn the adjusting screw (25, Figure 6) counter clockwise
to advance the tape, clockwise to delay it. Tighten the clamp screw securely and recheck
switching as above.
• The lift lever should be adjusted so the lifting stud passes over center with the
lever down firmly against the base plate. If adjustment is required, loosen the eccentric bolt,
and turn the eccentric (25, Figure 13) so the lever locks over center.
CAUTION: Do not move the depth adjusting screw (28} for this screw adjusts
upper contact (N/C) pressure .
5. 3 Drive System Parts Replacement
To replace damaged gears or shafts, loosen all set screws clamping gears to
the shaft. Slide the shaft through its bearings. Take care to preserve all the shim washers
disassembled.
When re-assembling components, re-insert the shaft through its bearings, pick-
ing up shim washers, gears, or other components one at a time. Be sure to re-assemble all
shim washers in their proper places. This will usually keep shaft end -play and gear backlash
within the tolerances shown in Table 5. 3-1. It may become necessary to add or take away
shims when new gears are installed.
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TABLE 5.3-1.
CAPSTAN DRIVE SYSTEM TOLERANCES
Part
M oveme nt Max.
Mln.
Motor Input Shaft
End Play
.010
.00 1
Auxiliar y Drive Gear
End Play
.010 .001
Capstan Shaft
End Play
. 005
.00 1
Spider Beve 1 Gear
End Play
. 005 .001
5.3. 1 Escapement Assembly Adjustment
If any parts of the escapement a ssembly have been repaired or replaced, adjust ·
the assembly to pr o vide the clearances shown in Fi g ur e 16.
WITH SHIM
.000- .001
ARMATURE IN
PICKED POSITION
I
.~
TIP CLEARANCE
. 010± . 003
100 GRAMS TENSION
Figure 16. Escapement Adjustments
6.0 TAPE SPLICING
Care sho uld be taken in splicing tapes to help prevent er ro ne ous reading. If a rough j oin t is
made, the leading edge of the tape catches the star wh eel (when reading no-hole) so that it starts
to roll over the splice . This action, represe nted in Figure 17a, does not produce an erroneous
reading in itself , but if the joint is just forward of a perforation, the star wheel, after r olling over
the rough edge, straddles the perforation as shown in Figure 17b, and the characte r will not
be read .
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Figure 17. Bad splice showing star wheel (a) catching on
edge of tape and starting to roll into positi on,
(b) straddling the following perforation
Reading errors can be prevented by observing proper techniques in splicing the tape as
follows:
a. The tape should be cut straight across through the center of the sprocket hole as shown
in Figure 18 . This permits the star wheel to slide into the perforation properly, or if no per-
foration exists, the star wheel will roll over the splice and yet be in position to read a character
on the next step. Allow approximately 1/2 inch for splice overlap.
b. Taper the ends of the tape prior to ceme nting with sandpaper. A fingernail board is an
excellent tool for this purpose .
c. Apply a light coat of contact cement to the tape ends, and after drying thoroughly, sand
the joint smooth. ·
0 0
00 0
0 0 0
00 0
0 0
0000000
00 0
0 0 0
0 0
TAPE CUT ~HROUGH
CENTER OF HOLES
~TAPERED EN~S
0 0 ,l 0
o yo
0 0 I
0 s
0 0 0
0000 00
00 A
0 yO
0 0
Flgure 18. Bl-directional Tape Splice
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7.0 SPECIAL ACCESSORY EQUIPMENT
7.1 End-of-Tape Sensing Switch
7.1.1 Description
The end-of-tape sensing switch is designed to provide a contact transfer to indi -
cate the end of a tape regardless of its direction of movement. Either the "make" or "break"
signal may be used depending upon the logic requirements of the system.
7 .1.2 Mechanical Operation (See Figure 20)
A lever actuated sensing switch is mounted on the inside face of the read head
stripper plate . The r olle r on the end of the switch actuator protrudes through a slot in both the
stripper plate and tape pressure guide. When tape is under the tape guide, the switch contacts
will be transferred to the normally open position due to tape pressure against the switch actuator. ·
When no tape is present, the switch contacts will be in the normally closed position. One sensing
switch is positioned on each side of the capstan so that end-of-tape is indicated whether tape is
moving in either the forward or reverse direction.
7.1.3 Electrical Operation
The sensing switches use form "C" co ntacts, and as shown in Figure 19, contacts
are in the normally close d (NC) position when no tape is under the pressure guide.
- - - - "-"' r A - - - ""
( '' ) ( II )
N~ r,;0 -- io~ --;J~
Figure 19. Schematic Showing Switches Indicating End of Tape
Alternate logic for "end -of-tape " switching may be easily arranged by removing
the stripper plate , disconnecting the wires from the NC switch terminals, and reconnecting them
to the NO terminals .
7.1.4 Adjustment
The roller on the switch actuator should protrude through the stripper plate 5/64
inch, so that when tape is moving under the tape pressure guide, the switch will be closed. This
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. .. ·
adjustment can be made by loosening the two mounting screws (Figure 20) on the o utside face of
the stripper plate and moving the block assemb ly up or down. The tape pressure guide should be
adjusted so that there is . 015" -.020" clearance between the stripper plate and guide.
MOUNTING
SGREWS STRIPPER
PLATE
Figure 20. End-of-Tape Switch Adjustment :
7.2 Capstan Shaft Commutator
7.2.1 Description
(a) switch sensing end of tape ;
{b) switch sensing tape
The co mmutator unit is designed to provide a " free-running" o perational mode,
and thus permit tape reading without using a tape reading pulse genera tor . The normal "tape-
stepping" mode of the standard reader is retained as an optional o pera ti ng mo de. To obtain
"free-running", an integral commutator generates a switch closure signal that has an adjustable
duration which is discreetly related to the capstan velocity, and whose phase is adjustable and
related to the tape hole and star wheel reading position. Switch closur e and phase angle is ad-
justed to fulfill specific customers requirements .
7 .2.2 Mechanical Operation (See Figure 21)
A commutator is directly driven by the read head capstan shaft and is mounted
just to the rear of the capstan bearing support plate. Two adjustable brushes are located on
either side of the commutator and are supported by the capstan bearing plate . The commutator
is composed of 20 angular segments, each 5 degrees wide. Segments are equally spaced, center
to center, every 18 degrees of arc. The commutator segments are printed circuit .s retained on
an aluminum hub. The commutator is locked in position on the capstan shaft with a set screw .
The two sets of brushes are made of multiple wires retained in a nylon brush
holder . The brush holders, held in position with a screw, may·be moved for adjustment of both
duration and phase angle of the commutator switch closure.
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TO PIN b OF CONNECTOR
\
TO PIN a OF CONNECTOR
CI RCUIT BOARD
------- -------- \ ~~\) ----.
BRUSH
CAPSTAN REAR
BEARING PLATE
BRUSH"B" CARR I ER
Figure 21. Capstan Commutator
7 .2.3 Electrical Operation
With every revolution of the ca pstan drive s haft there are twenty series circuits
completed through the two brushes and the twenty commutator segments. Through these series
circuits from Brush A to commut at or and out to Brush B, s witch closures are generated during
each angular 18 degree increment of capstan revolution. Current through the com mutator must
be limited to 10 milliamperes maximum.
Because each brush holder can be independently adjusted, both switch closure
duration and phase angle is adjt1sted to customer specifications. The timing diagram of Figure
22 illustrates the flexibility of these adjustments.
7 .2.4 Adjustmen t
When both brushes are set so as to engage their commutator segment contacts at
exactly the same moment , the switch closure angle will be at its 5 degree maximum duration.
The phase relationship between the switch closure angle and capstan increment may be altered,
maintaining the same switch closure angle, by moving both brushes an equal distance in the same
direction of travel.
In order to change the width of the switch clos ure angle, one brush holder, or both
if desired, may be moved so that the brushes do not engage their respective commutator segments
at the same time. It is possible to diminish the closure angle to zero by this adjustment.
IMPORTANT : When making any brush adjustments, always keep finger pressure on
the brush holder towa!"d the caps tan drive shaft. This is necessary in order to insure proper
brush radial alignment.
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I 3/ 8
....+--------------.. l
5- 3/ 4 8 -23/ 32
l__ _· -~~-1- / _4_W_i_d_e_S _lo-ts~~~~~~~~~-JJ
1-31 / 64 -
~ 19 .l
1.2 Description
Rack Mount Hole Pattern For Panel Model Reader
Dimensional tolerance ! . 020
The Tally Model 424 Tape Readers, Figures 1, 3, and 4, are self-contained bi-direc-
tional, asy nchronous devices for reading any standard perforated tape. Tapes having five to
eight levels of information may be interchanged and read without reader adjustment. The reading
rate is variable from 0 to 60 characters per second in either direction of tape feed. Tape wear
is exceptionally lo w, and standard paper tape may be re -read hundreds of times.
Model types and ass oc iated tape handling facilities:
Model
424 c
424 CF
424 p
424 PF
424 PR
Cons ol e Model
"
Panel Model
"
Tape Handling Facility
No Tape Handling
Fan Fold Tape Handling
No Tape Handling
Fan Fold Tape Handling
Reel Tape Handling
The panel model series ar e mounted on an anodized aluminum panel 1/ 4" x 8 -23 / 32 x 19".
Refer to Section 1.1 for rack mounting dimensions.
Drive power is supplied to the capstan from an integrally mounted 1/ 30 HP motor
through a bevel gear and differential drive assembly. The use of special clutches in the drive
assembly permits high speed resi)onse for bi-directional tape movement.
1.3 Input Requirements
The drive motor (1 /30 HP) requires 105-125 volt AC, 'so cps, at 0.4 amperes. To move
the tape, a 4.5 ± 0.5 millisecond DC pulse (rise time less than 0.5 millisecond) of 48 or 24 ± 10%
volts (according to c ustomer specification) is applied to either the forward or reverse escape-
ment assembly. One pulse must be supplied for each movement of the tape.
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~~ -v ~
~'--+-=-~=-~-0----=:_- -o
Escapement .
Coil
D= r=-i~v~e..-:v_o_i_t_a_g_e __ ,__ -- · ------------------------------------------~ Q_n Coil _ -
Commutator
(DC Voltage)
Contact
Switching
Capstan rpm a~ specified by cu~tomer
-1
------
No Hole
111111m111111
Hole
111111•111111
Tine -
.
Figur e 22. Commutator Timin g Diagram
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7. 3 PLUGABLE READ HEAD
There is also available as optional equipment a read head in Modular Plug-in form. This
permits rapid replacement of this entire unit. consisting of the fixed contacts, moving contacts,
star wheels and star wheel levers. This approach is ideally suited for customers using several
readers in one location; by stocking one spare read head. the spare parts on hand are then held .
to a minimum.
8. 0 PARTS ORDERING AND PARTS LIST
To order a replacement part, refer to Figures 23, 24, 25, 26, 27, 28, 29 and 30. Find
the part required, and order by part number and name listed. Give the model and serial nuJ!l-
ber of the reader on which it is to be used.
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