UnionSpecial 39500AB Instruction sheet

ST Y LES
39500AB
39500AC
39500A
CATALOG
No.
103AB
•
INDUSTRIAL
MACHINES
CLASS 39500
STREAMLINED
HIGH SPEED OVERSEAMERS
CHICAGO
•
®
From the library of: Superior Sewing Machine & Supply LLC

Catalog No. 103 AB
(Supplement to Catalog No. 103 S)
INSTRUCTIONS
FOR
ADJUSTING AND OPERATING
39 500 AB
LIST OF PARTS
CLASS 39500
Styles
39500 AC 39500 AE
The parts listed in this catalog are
furnished at list prices for repairs only.
First Edition
Copyright 1960
by
Union Special Machine Co.
Rights Reserved in All Countries
MACHINE COMPANY
INDUSTRIAL SEWING MACHINES
CHICAGO
Printed in U.S.A.
---- -------- -·----
From the library of: Superior Sewing Machine & Supply LLC

IDENTIFICATION OF MACJITNE
Each Union Special machine is identified by a Style number which is stamped
into the name plat e.
Machines similar in construction are grouped by a Class number, which
contains no letters. Example:
11
39500
11
• Letters suffixed to a Class number
i ndicatesthe standardStyleof a machine. Example: "39500 AB". I:..etter "Z"
is reserved as a suffix to the standard Style identification to specify machine
is of "Special" construction.
APPLICATION OF CATALOG
This catalog is a supplement to Catalog No. 103 S and should be used in
conjunction. Parts illustrated in this catalog represent parts not used in
39500 A, B, P or AF machines. For clarity, certain 39500 A, B, P and AF
parts are shown in phantom to help locate 39500 AB, AC and AE parts.
Opposite the illustration page, parts are identified by detail number, part
number, description, and amount required.
Adjusting and operating instructions included represent only areas
concerned with 39500 AB, AC and AE.
This catalog applies specifically to the standard Styles of machine as listed
herein and can also be applied with discretion, to some Special machines of
Class 39500. References to direction, such as right, left, front, back, etc.,
aretakenfromthe operator'sposition while seated at the machine. Operating
direction of handwheel is away from operator.
STYLES OF MACJITNES
Two Needle, One Looper, One Spreader, Three Thread, Low Throw Over-
seaming Machine. Differential Feed, Trimming Mechanism with Spring
Pressed Lower Knife, Automatic Lubricating System.
39500 AB For closing women's seamless nylon hosiery. Seam specification,
Special SSa-1; standard seam width is approximately 3/32 inch. Stitch
range 20 to 100 per inch; standard setting 80 per inch.
39500 AC For closing men's hosiery. Seam specification, Special SSa-1;
standard seam width approximately 1/8 inch. Stitch range 20 to 100 per
inch; standard setting 35 per inch.
39500 AE For closing women's seamless hosiery. Prepared for Paramount
Attachment. Seam specification, Special SSa-1; standard seam width is
approximately 3/32 inch. Stitch range 20 to 100 per inch; standard setting
70 per inch.
OILING
CAUTION! Oil was drained from machine when shipped, so reservoir must
be filled before beginning to operate. Oil capacity of Class 39500 is six ounces
6
A
straight mineral oil of a Saybolt viscosity of 200 to 250 seconds at 100
Fahrenheit should be used.
Machine is filled with oil at spring cap in top cover. Oil level is checked
at sight gauge on front of machine. Red bulb on oil level indicator should show
between gauge lines.
3
From the library of: Superior Sewing Machine & Supply LLC

OILING (Continued)
Machine is automatically lubricated. No oiling is necessary, other than
keeping main reservoir filled. Check oil daily before the morning start. Add
oil as requi r ed.
Drain plug screw is located at back of machine near bottom edge of base.
It is a magnetic screw designed to accumulate possible foreign materials wh i ch
may have entered the crank case. It should be removed and cleaned periodically.
NEEDLES
Each Union Special needle has both type and size number. The Type number
denotes the kind of shank, point, length, groove, finish and other details. The
size number, stamped on the needle shank, denotes largest diameter of blade,
measured in thousandths of an inch, midway between shank and eye.
Collectively, type and size number represent the complete symbol which is
given on the label of all needles packaged and sold by Union Special.
39500 AB, AC and AE use a curved blade needle. The standard needle for
these styles is Type 154 GCS. It is a slabbed shank, round point, • 046 inch
double slab, standard length, curved blade, double groove, struck groove,
spotted, chromium plated needle in sizes 025, 027, 029, 032.
To have needle orders promptly and accurately filled, an empty package,
a sample needle, or the type and size number should be forwarded. Use
description on label. A complete order would read: "1000 Needles, Type
154 GCS, Size 025".
Selection of proper needle size is determined by size of thread used. Thread
should pass freely through needle eye in order to produce a good stitch formation.
Success in the operation of Union Special machines can be secured only by
use of needlespackagedunderourbrandname, ~ which is backed
by a reputation for producing highest quality needles in materials artd workman-
ship for more than three-quarters of a century.
CHANGING NEEDLES
Release pressure on presser foot by turning presser foot release bushing
(N, Figs. 1 and 2), and swing presser arm (E) out ofposition. Turnhandwheel
in the operating direction until needles are at their lowest point of travel.
Using hexagonal socket wrench, No. 21388 AU, furnished with machine, loosen
needle clamp nut about 1/4 turn. Again turn handwheel until needle s are at
high position; withdraw needles.
To replace needles, leave needle holder at high position and, with the flats
to the left, insert needles in holder until they rest against the stop pin. Keeping
needles in this position, turn handwheel until holder is aga in at its low point of
travel, then tighten nut. Return presser arm (E) to position; re-lock presser
foot bushing ( N).
4
From the library of: Superior Sewing Machine & Supply LLC

THREAD STAND
39500 AC ONLY
After thread comes from thread cones (positioned on cone support (P)), it
is brought up through BACK thread eyelet, then down through FRONT thread
eyelet (R, Fig. 1). Next, thread is extended down through the right hand hole
and up through left hand hole of the tension thread guide wire (A) • Thread is
then continued between tension discs (W), through slot (VL and on through
thread guide (B) •
39500 AB AND 39500 AE ONLY
After thread comes from cones (positioned on cone support (P)}, it is
brought up through the BACK thread eyelet, then continues between felt pads
(X) through slot (V), and down through FRONT thread eyelet (R, Fig. 2).
Next, thread is extended down through the left hand hole in the tension thread
guide wire (A), through holes in the thread guide (B).
THREADING
Only parts involved in threading are shown in threading diagrams
(Figs. 1 and 2). Parts are presented in their relative positions for clar i ty .
The following recommended procedure simplifies threading: Beginning with
complete threading of upper looper, progress to complete threading of right
needle, and conclude by complete threading for left needle. Steps for threading
are given below.
Prior to threading, swing cloth plate open, turn handwheel in operating
position to bring needles (M) into high position. Release pressure on presser
foot by a counterclockwise turn of the release bushing ( N), and then swing
presser arm (E) out of position.
CAUTION! Make sure thethreads, as they extendfrom the tension thread
guide wire (A, Figs. 1 and 2), are between tension discs (W) and in diagonal
slots (V) of the tension posts (U).
TO THREAD UPPER LOOPER
Turn handwheel until point of upper looper (L) is all the way left. Lead
thread through auxiliary looper thread eyelet (C) from back to front, then
through both eyes of upper looper thread eyelet (D) from left to right. NOTE:
Thread must pass in front oflooperthreadpull-off (F). After pulling up upper
looper thread tube assembly (K), lead the thread under neck of top cover casting
and down through thread tube assembly (K). This is easily accomplished by
using the forked end of the threading wire, supplied with each machine.
Pull thread out bottom oftube using hooked end oftweezers, also supplied with
each machine. Push tube down, and then insert thread through upper looper
eye from front to back.
CAUTION! Be sure upperlooperthread is under the needle threads when
passing from tube assembly to upper looper eye.
TO THREAD NEEDLES
Turn handwheelin operating direction until n ee dles (M) ar e at their high e st
position. Insert both needle threads from right to le ft, throu gh BOTH eyes of
needle thread eyel et (H), under neck of top cover ca s tin g a nd then down throu gh
holes in top cover needle thread eyelet (J). The r ig ht n ee dle thread should be
threaded in the ri g ht hole and the left needle thre ad throu gh the left hole of the
top cover needle th read eyelet. Thread needle s from the fr ont.
THREAD TENSION
The amount of tension on the ne e dle and loope r thr ea ds is regulated by thr ee
knurled tension nuts (S, Fi gs. 1 and 2). Tens i on on thre a ds should be only
sufficient to secure proper st i tch formation.
5
From the library of: Superior Sewing Machine & Supply LLC

~~ T e ns i on Nut
m Tens i on Post
U s lot
rlJ Tension Discs
n Te n sion Thr e ad
fal Guid e Wire
r.:ii'I Auxiliary Looper Thread
i!IJ Eyel et
l'i:t Upper Looper Thread
~ Eyelet
F ig . 1
For Style 39500 AC
6
one Support
r Looper Thread
As s embly
From the library of: Superior Sewing Machine & Supply LLC

m Te ns i on Po st
U s lot
l'f:ll Te nsion
~ Discs
Et Tens i on Pads
NOTE: Tension pads (X)
are used only with thread
stand eyelet (R) and
tension discs (W) are
i nverted at (R) only.
n Tension Thread
ifa1 Guide Wire
m Thread
r.iii Auxi.liary Looper Thread
~!! E y elet
l'ii:l upper Looper Thread
~!'.~ Eyelet
~~ Presser Arm--------
Fi g. 2
For Styles 39500 AB, AE
7
one Support
Top Cover Needle
Thread Eyelet
r Looper Thr ea d
Assembly
r Looper
From the library of: Superior Sewing Machine & Supply LLC

PRESSER FOOT PRESSURE
Sufficient pressure to feed the work uniformly
should be maintained. Should it be necessary to
increase or decrease amount of pressure on
presser foot, loosen lock nut (A, Fig. 3), and
turn adjusting screw (B). Adjusting screw has a
right hand thread; tightening will increase
pressure, loosening decreases the pressure.
When pressure adjusting screw (B) has been
properly set, tighten the lock nut (A). With
presser foot resting on throat plate, position
locking nut (C) so that its under surface is
approximately 1/32 inch to 1/16 inch from the
top surface of the adjusting screw (B). Set cap
(D) against locking nut (C).
FEED ECCENTRICS
Fig. 3
Feed eccentrics used in the 39500 AB machine have been selected to
produce approximately 80 stitches per inch. On the 39500 AC machine,
eccentrics have been selected to produce approximately 35 stitches per inch,
and on the 39500 AE machine, eccentrics have been selected to produce
approximately 70 stitches per inch. It will be noted on the 39500 AB machine
that the part number of the main feed eccentric is No. 39540-100, while that
of the differential feed eccentric is No. 39540-70. Minor numbers of the part
symbol indicate approximately the number of stitches obtainable when using
that eccentric. Unless otherwise specified, the 39 500 AB machine will be
shipped with above combination of eccentrics. The 39500 AC machine will be
shipped with 39540-60 main feed eccentric and 39540-30 differential feed
eccentric, while the 39500 AE machine will be shipped with 39540-70 as both
main and differential feed eccentrics.
Generally speaking, differential (right hand) feed eccentric determines
number of stitches produced. Main (left hand) feed eccentric is selected in
relation to degree and direction of stretch of material being sewn, or type of
operation.
Following stitch number feed eccentrics are available under No. 39540- 4,
5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34,
36, 40, 50, 60, 70, 100. Only two eccentrics are supplied with each machine.
Additional eccentrics may be ordered separately. To order, use No. 39540
with a minor number suffixed to indicate number of stitches desired.
Example: 39540-70.
Fig. 4
ASSEMBLING AND ADJUSTING SEWING PARTS
Before assembling sewing parts, remove cloth plate,
fabric guard, chip guard, upper knife assembly, lower
knife holder assembly. Then, follow this suggested
sequence:
SETTING THE NEEDLE
With throat plate in position, needles should center in
the front end of needle slot. When needles are at high
position, the needle points should be set 15/32 inch above
throat plate (Fig. 4) for 39500 AC.
8
From the library of: Superior Sewing Machine & Supply LLC

Fig. 6
SETTING THE NEEDLE (Continued)
For 39500AB, 39500 AE
the needle points should be
set7/16inchabovethethroat
plate. Move needle driving
arm (A, Fig. 4) byloosening
clamp screw (B). Remove
throat plate.
At this point, insert
lower spreader (A, Fig. 5)
into bar (C). With lower
spreader at the left end of its
stroke, set the spreader
point 1/8 inch from center of
left needle, using looper
gauge No. 21225 G-1/8. Do
not have lower spreader
de f1 e c tin g the needles.
Tighten nut (B).
SETTING THE REAR NEEDLE GUARD
Fig. 5
Set rear needle guard as high as possible (A, Fig. 6) without interfering
with either lower spreader or movement of lower knife holder, but still in
position to deflect needle forward. 002 to • 004 inch. Screw (B) is used to set
the rear needle guard. Make sure there is no interference between the rear
nP.edle guard and lower spreader.
SETTING THE LOWER SPREADER
Now, finish lower spreader adjustment. As
spreader moves to the right, its point should be
set into the needle scarfs (A, Fig. 7) until needles
spring forward from rear guard surface another
• 002 to • 004 inch.
SETTING THE FRONT NEEDLE GUARD
Assemble front needle guard ( C, Fig. 6).
When lower spreader is springing needle off back
Fig. 8
guard, set the front needle
guard as close as possible to
needles without touching.
Screw (D) is used to adjust
and set front needle guard.
After this setting, make F ig. 7
sure there is no interference
between the needle guards and di ff er e ntial fee d do g.
SETTING THE UPPER LOOPER
Insertupperlooper(A, Fig. 8) inits holder. Screw (B)
holds upper looper in its holder and permits it to be pushed
in or out or turned around its shank. Insert upper loop er
holder into upper looper shaft (if not already in place).
9
From the library of: Superior Sewing Machine & Supply LLC

SETTING THE UPPER LOOPER (Continued)
Screw (C) on the clamp holds the upper looper holder in the shaft. Locate
upper looper in its holder so that the shank extends 1/32 to 1/16 inch beyond
holder (Fig. 8).
When the upper looper is at the right end of its stroke,
upper looper holder should be set to position upper looper
shank back of vertical.
Next, turn the handwheel until looper is at the left end
of its travel. Check the dimensions of the upper looper
point with respect to needle and throat plate (Fig. 9) and
the following dimensions; distance from centerline of left
needle to point of looper should be approximately 5/3 2 inch
and distance from throat plate to point of looper should be
approximately 15/32 inch on 39500 AC machine.
NOTE: ForStyles 39500AB, 39500AE, the dimensional Fig. 9
setting of the upper looper point with respect to throat plate
is approximately 7/16 inch. If resetting is necessary, do so by moving the
upper looper holder (A, Fig. 9).
When the correct setting is obtained, it can be checked
quickly as follows: As upper looper is moving to the r i ght,
when upper looper eye centers on the right needle, the eyes
of the upperlooperandrightneedle should align (Fig. 10).
Check setting to avoid interference between upper
loope r and needles on needle down stroke. If needles rub
the back of upper looper. pull looper out of its holder
slightly and rotate a short distance counterclockwise.
looking from left end of machine. Reset to maintain
dimensions suggested above and in Figs. 9 and 10.
SETTING THE FEED DOGS
Fig. 10
Assemble and set the differential feed dog (A, Fig. 11)
and main feed dog (B) so that top surfaces of the feeding surfaces all lay in the
same plane. This can be
checked by sighting across
feeding surface with a
straight edge. Feed sur-
faces should now be leveled
with the throat plate sur-
faces by rotating feed tilting
adjusting pin (D). This pin
raises or lowers the back
end of both feed bars at the
same time.
The feeding surfaces
should be set level at the
time feeding surface first
appears above the throat
plate. Screw (E) locks feed
tilting adjusting pin in place.
Fig. 11
10
From the library of: Superior Sewing Machine & Supply LLC