Seiko TH-2B User manual

Operating Instructiona
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* T H - 2 B
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* T H - 6 B *
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* T H - 7 B *
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* T H - 8 B *
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SEIKO SEWING. MACHINE CO.
From the library of: Superior Sewing Machine & Supply LLC

Contents
1 Lubrication 2.
2 Setting the needle 2
3 Thre ad 2
4 Removal and insertion of bobbin ' 3
5Winding the bobbin thread 4
6 Needle threading 5
7Tension of bobbin thread and needle thread 5
8Pressure of presser foot 7
9Adjustment of stitch length 7
10 Determination of positioning for stitch length at
forward and backward amount 7
11 Timing of thread tension releasing mechanism ..i....... 8
12 Removal shuttle hook 9
13 Adjusting on the each points g
(A) Adjusting needle position against needle hole
of feed dog. (7B & 8B Types) 9
(B) Adjusting the height of feed dog 10
(C) Adjustment for timing of feed dog-rise 10
(D) Adjusting the forward and backward position of
needle bar frame 10
(E) Timing of needle and hook
® Positioning between the upper side of needle eye. 11
® Adjusting the height of needle bar 11
®Adjusting the position of the tip of hook 11
® Adjusting the clearance between needle and the tip
01 hook 12
® Determination of the position of needle bar
rock frame for 7B & 8B 12
®Each timing for up/down moving amount of presser
foot (2B & 8B only) I3
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Specification for Model TH Types
Max. Sewing speed:
Needle:
Feed mechanism:
Presser lift:
Needle bar stroke:
Bed size:
Working space:
Use:
800 (s.p.m.) ,
Sewing speed may be changed by the
models and applications.
DD X 1, BY X 1 (forTH-2B)
(8B) Alternating pressers
(7B) Flat presser;
(6B) Roller or flat presser
(2B) Alternating pressers
20mm (10mm by lever)
56™"
253inm x 656mm
180mm X 400mm
Suitable for sewing of extra heavy
materials such as shoeSf bagSt leathert
sproting goods and thick fabrics*
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1 Lubrication
Lubrication all points indicated by arrows in figures.
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Setting the needle
Tii-rn +hP balance wheel over tov/ard you until the needle "bar
ita hisLst Mint. Loosen the needle clamp sorew(l).
Sold Ind insert the Ledle(2) into the needle bar hoi® "P
as deeply as it will go, keeping the long groove of the
needle to the left and tighten the set sorew(l) securely.
3 Thread
The needle thread should be used the left—twisted thread only»
the bobbin thread can be used either left or right twisted
To find out thread twist, hold the thread as shown by illust
ration, and turn the thread over toward you between the thumb
and forefinger of right hand, and then left-twisted thread
will wind tighter strands, and right-twisted thread will
unwind.
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4 Removal and insertion of bobbin
ORemoval of bobbin
Open the bed slide, then observe the hook position (as shown
figure) and drop-do^ the needle bar at lowest point, then
apring(l) and bobbin
caseu) and depress the snap spring and pull up the bobbin
case outward and take the bobbin out of the bobbin case. •
b
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OInsertion of bobbin
Put the bobbin(4) into the bobbin easel5) while holding
down the thread and pass the thread through underneath the
bobbin case spring!6; to lead it out from the bobbin case
slit(7).
5Winding the bobbin thread
Pass the thread in the order numerically instructed
in figures.
(1) Spool pin—^(2) Thread guide (am)-^(3) Needle
teneion thread guide »-the clearance between two
tension discs »-(4) Meedle thread tension thr^d
guide—?-(5) Bobbin (winding several timesj ^
(6) Move the bobbin winding lever#
un-\U
Winding length should be adjusted^by the screw(7) and
left & rightward positioning of the lever(6).
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6 Needle threading
Pass the thread in the order numerically instructed
in the figures.
Spool pin—^(2) Thread guide of thread tension
(3) Clearance between two tension discs ^(4) Thread
guide of thread tension ^(5) Thread controller discs
® single turn >-(6) Thread guide 5^
Tension spring ^(q) Thread take up levIT^^
-I el
^7^ Tension sprffig_~^'(g)
(9) Thread guide on face plate
(11) Needle
-^(10) Needle clamp
Tension of bobbin thread and needle thread
Balanced tension
(A) When stitch tension is well balanced, the bobbin thread
IS enpged with the needle thread at the center of given
material thickness, as shown by fig. (A)
(B) Tight needle of loose
bobbin thread tension
(B) Pig. (B) shows unbalanced tension, tight needle thread or
loose bobbin thread.
(C) Loose needle or tight
bobbin thread tension
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Adjusting needle thread tension
By turning the tension regulating
nut clockwiseneedle thread
tension increases.
By turning the tensionregulating
nut counter-clockwise^^^ needle
thread tension decreases.
S
Adjusting hoBbin thread tension
By loosening set screw(l) and tension regulating
screw(1).
The set screw(l) should exactly be tightened after
the bobbin thread tension was adjusted.
By turning the tension regulating screw clockwise/^
thread tension increases and by turning the tension
regulating screw counter—clockwise thread tension
decreases.
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8 Pressure of presser foot
Loosen the nut, then turn the pressure regulating thumb screw
clockwise^^pressre increases turn the pressure regulating
thumb screw counter-clockwise^^>.pressure decreases,
^ter adjustment, tighten the nut. Adjustment should be made
in accordance with the materials to be sewn.
lU (ill
Adjustment of stitch length
lever(l), reverse stitch is performed,
perfSLld! regulating lever{l), forward atitlh is
knurling nut(2) 4 (3) clockwise/'"^ feed length
deoreasea, Md by turning the knurling nut(2) &(3) oounte?-
increases. The knurling nut(2) &
ias determined ®^ ®^^®^ desired stitch length
}^: ikO /. - A
(Note)
When upward &downward movemei
of the feed regulating lever ;
loosened, the feed adjusting
screw(4) should be tightened,
10 Determination of positioning for stitch length at
forward and backward amount
Equivalent stitch length at forward and backward can be
obtained by adjustment of t upward & downward position of
feed regulating set plate(A)-, and back-lever(feed regulat
ing collar B) should be placed on feed regulating set plate (A)
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11
Timing of thread tension releasing meohanism
(a) When moving the lifting lever(l), upper
thread should be adjusted so as to Sdo.
(b) Adjustment
Pull-up the presser "bar lifter(3), the
clearance should be made over 3mm between tip
of the tension releasing plate(4) and tension
disc(5) and tighten the screws(2) on the tension
releasing plate.
—
ii
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12 Removal shuttle hook
Pull-down the opening & closing
lever(A) instructed in the fig-li
tnd then pull-down It rlghtward
and remove -t—the outer hook ring
(B) at the raised position oi
feed dog instructed in the
Pig-3 shows removal of the shuttle
Setting the shuttle hook can he
made in the contrary order of
the above description.
rig- 2
Fig- 1
ri
13 Adjusting on the each points , * x. f7-B
(A)Adjusting needle position against needle hole of feed dog.(
Ledle^hoild he positioned
feed dog and moved together , the amount
out) of feed shaft ("PP®r\acrew(3) and needle
screw(3) •
(Needle dorpping point
is to be set at the center
of needle hole of the feed
dog.)
(Note) ^ . .. .
Peed shaf t(upper) connector( AU4;
should be fixed by the screw(3)
without moving feed shaft(upper)
connector(A)(4).
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(B) Adjusting the height of feed dog
sh^t o ^ lower
ah^t oonneotor set screw
8hlft?pf "PP®'' ^ lower
aMit(2) la adjusted at
eod downwird!
„\^® -®^ace of'^e^'e'^
feed^do/shouid
at PLUS^lwus +n K ®^J*i3ted
the materials to Se fe,^.
(C)Adjuatment for timing of feed dog-rise
I —
'r
L^LIS
a
ZISlr
and vihfating foot hf' ^®®'^ '^og
position. AdjustSenI ''® ®«°a
lipper & lower f ^d «« "^wo
aorews(l) showf"^ 116-5^(85"'
^^^hoiltiin® forward and backward
position of needle bar frame
ri'T^s »• rHis e:?c:
16—17m*
0
L.
Ot
Adjustment of the clearance between
presser bar and needle bar is to be
made by the acrew(l).
-10-
O
imlQ 2
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(E)Timing of needle and hook
® Positioning of needle and the tip of hook
When the needle bar has risen 4.5nutt -5.5mm
from its lowest positioni the tip of the
hook should meet the center line of the needle
4^
2.3niiii'—3iaa
V *4-
4.5iDni'-~5> 5iiun
Distance between the upper side of the needle-eye
and the tip of the hook should be 2.5mm — 3mm.
©Adjusting the height of needle bar
Loosen the screw of needle bar connecting 3tud(2)
by wrench which inserts to the hole(l) of arm and
adjust the needle bar{3) ^ upward and downward.
©Adjusting the position of the tip of hook
Loosen the screw(4) of the shaft crank by
spanner, then determine the forward or
backward (high or low speed) of the tip
of hook. Tighten the screw(4) after
adjustment.
£
m n
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©Adjusting the.clearance. be tween needle and the tip of hook
Pig-- fi
Loosen set screw(l)for hook
rock frame, then outer hook
should be mo-ved"4—^ right-
ward or leftward. (Fig. 6)
needle
@
Ij aP / - tip of
— hook
tip of hook
—0.05—0.3mn
©determination of the position of
lieedle bar rock frame for 7B & 8B
needle bar rock frame hinge stud,
fdt ooai the needle bar rock frame hinge stud(small)
(4) positioned lower part of needle bar rock frame(2), and also the
2^ needle bar rock frame hinge stud(large) (6).
® ^ ^Se stud(large)(6) to
° moving the needle bar rock frame leftward &
of thT the balance wheel, determines smooth position
of feed dog needle and center of the needle hole
position, tighten the set screw(l)of
r -fclie needle bar
Inn^ ^ hin^ stud(small)(4) to slightly the needle bar bar
rock frame position bracket(8).
needle bar rook frame hinge stud(large) (6) to the aide
wh«i f ^ frame(2), and then turn the balance
wheel and tighten the each screw exactly.
looseness of the leftward & rightward ^ of the needle
stitoh^skipplng resulted in the breaking of needle,
12 -
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@Eaoh timiag for up/down moving amount of presaer foot (2B & 8B only)
a Timing of inside preeser Snwnina the^lever°®
before needle—eye reaches to feed dogi after downing
of nrlsaei- bar lifter, turning the balance wheel toward you.
AdjS^ln? irmade by two set torews(2) of upward & downward
By^up"! doTO^lifting eooentriot-1'inside Presser foot against
needle is touch with feed dog either speedily or slowly.
As for 2B Type, adjusting feed dog and outer presser foot
to
set at same point on the upper face of the needle plate.
b For the setting of inside presser foot and outside presser
foot e(iuivalently, the lifting eccentric connection crank
pinch acrew(3) io "to be adjusted.
Ajustment should be made by the materials being sewn.
c Up/down moving amount of inside presser foot and outside
presser foot
can be obtained by loosing the screwt4;.
Upthe 3crew(4)i the amount increases.
Down the screw(4) , the amount decreases.
J
— 1 3 —
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1. POSITION OF CAM(i^^28102) FOR CONNECTING ROD
Turn the h^Andwheel until the needle bar lowers by O.ifmm from
its top dead center. At this point, set the cam(;^f28l02) with
the groove on the cam faces the top.
( or -l^urn the cam, /'/28102, to make i^mm distance between the groove
on the cam and the center of the upper shaft when the needle is
at its highest point shown as the following figure.)
And tighten the screw(a) securely.
//28102
center of
upper
shaft I
Groove.
1
• 1
1\
i
1^
* Needle lowers by 0.4 mm from
its highest point
*Needle at the highest point
2. POSITION OF FEEDING CAM(//28063)
STANDARD: When swaying the stitch length regulating lever(//28l6i|)
up and down at the point where the point of hook reaches
Imin this side of the needle, the feed dog and the needle
should be still.
HOW TO ADJUST:
(7B and 8B type)
Turn the feed cam(/ff28063) until the lower edge of the second
screw in rotating direction aligns with the upper edge of the
hole A on the cara(#28102) and tighten the screw(B). (Fig. 3 )
(6B, 2B and 2/RF type)
Turn the feed cam(J/28063) until the lower edge of the second
screw in rotating direction aligns with the upper edge of the
groove on the cam and tighten the screw(B). (Fig. 4 )
7p,oB ^^ype
F;,. 3
center of uppei
qhaf t
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3. HEIGHT OF NEE;DLE
STANDARD ; When the needle is its highest point, the height
from the surface of the needle plate to the lower
edge of the needle eye is 30• 5^0.5>nra,
f
pk'fe I
To make sure; The upper edge of the needle eye should reach .
part A of the needle guard on the shuttle driver)
at the needle is its lowest point.
30 S
e
POSITION OF SHUTTLE HOOK , , x
Turn the handwheel until the shuttle driver(#28/h51) reaches at
extreme left side. At this point, when contacting C part of the
hook with B part of the driver, the point of the shuttle hooktD)
should be at 1mm from the edge of the shuttle race(E).
For adjustment, loosen the screw(^2810it for Cylinder type, #28805
for Flat bed type)
PL/IT
TTft- .
_paPtf^
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;7^
4-
"t
6B. Zb.CH^RF
V
i • Ji
w—^
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