Seiko LSW-27BLK User manual

OPERATING INSTRUCTIONS
MODELS
LSW-27BLK
LTW-27B, •27BK, -27BM
SEIKO SEWING MACHINE CO., LTD.
TOKYO • JAPAN
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SPECIFICATIONS
SPEED: Maximum 3,500 r.p.m. (LSW-27BLK 2,400 r.p.m.)
(LTW-27BK . 27BM 2,800 r.p.m.)
NEEDLE: DPX7, #9 to #20 (LSW-27BLK DPX7, #11 to #22)
HOOK: Rotating hook
FEED: Drop feed and needle feed
STITCH LENGTH: 5mm (LSW-27BLK 6.5mm)
LIFT OF PRESSER FOOT: 7 mm (by a lever)
OILING: Semi-self oiling system
SIZE OF BED: 177 mm X 518 mm
MOTOR: 250W, 2P clutch motor
DIAMETER OF MOTOR PULLEY: 50 cycle 80^6, 60 cycle 65,6
(LTW-27BK • 27BM • LSW-27BLK 50 cycle 6656, 60 cycle 55?^)
NEEDLE GAUGE: 1/16" to 1-1/2"
(LTW-27BK . LSW-27BLK, 1/8" to 1/2")
(LTW-27BM, 5/16" standard)
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CONTENTS
Page
Setting up the machine 1
Oiling I
Oil adjuster 2
Needle 2
Thread 3
Inserting and removing bobbins 3
Winding bobbins and its adjustment 3
Threading the machine 4
Regulating
the thread tension 5
Adjustment of the presser foot pressure 5
Adjusting the stitch length 6
Reverse stitch 6
INFORMATION FOR ADJUSTMENT
Replacement of the timing belt 6
Adjusting the height of the feed dog 7
Adjusting the timing of the needle plate, needle and feeder 7
Adjusting the height of the needle bar 8
Timing between the hook and needle 9
Timing adjustment 9
Adjusting
the clearance 10
Relative position between bobbin case and opener 10
Adjusting the height of the presser foot 11
Fine adjustment of the needle feed 11
Changing the needle gauge 11
SPECIAL INSTRUCTIONS FOR MODEL LTW-27BK & LSW-27BLK...12
SPECIAL INSTRUCTIONS FOR MODEL LTW-27BM 20
LSW-27BLK
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SETTING UP THE MACHINE
Before setting up the machine on the table, attach the relative parts to
the table.
1. Hinge 2. Motor 3. Oil pan
4. Oil bottle 5. Knee lifter 6. Stand
7. Treadle 8. Machine rest pin 9. Cotton stand
10. Cushion rubber 11. Head of machine 12. V belt
13. Bobbin winder
Fig. 1 Fig. 1
OILING
Do not operate the machine, even if for testing, unless it has been pro
perly oiled.
(1) To fill the oil reservoir on top of the machine, pour oil through the
oil filler hole (A. Fig. 2) until the oil level reaches to the upper reference line
in the oil window (B. Fig. 2).
Oiling is automatically made by the vibration of the machine while sewing
operation through oiling wicks in the machine, and oil
flow stops automatically
when the operation of the machine ends.
Fig. 2
Fig. 3
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(2) The hook mechanism should receive careful attention whenlubricating
the machine.
Push open the slide-plates in the bed and pull out the oil gauges (C.
Fig. 2).
Fill oil in the reservoirs for the rotating hook mechanism up to the level
marked on each oil gauge.
Care must be taken that oil flow stops when oil level falls to the bottom.
(3) Oiling adjustment to the hook mechanism.
The maximum oil flow is made when the reference line on the oil adjusting
knob (2) is in a line with the point (1), and it stops when the reference line
is upright.
To adjust this, loosen the pinch screw (3) and turn the oil adjusting knob,
tighten the pinch screw.
OIL ADJUSTER
Oiling to inside of arm top cover is automatically made by the vibration
of the machine while sewing operation.
Stop oiling temporarily by the following method at your option in case
of long sewing operation.
When point of the dial enters into point of arm bed cover after turning
the dial, the dial goes, down and oiling stops completely.
NEEDLE
The size of the needle to be used should be determined by the size of
the thread, which must pass freely through the eye of the needle.
To insert the needle, turn the machine pulley over toward you until the
needle bar (1) moves up to its highest point, loosen the needle set screw (2)
and put the needle up into the needle bar as far as it will go, with the long
groove of the needle toward the inside direction and tighten the needle set
screw securely.
OIL ADJUSTER Fig. 4
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THREAD
CoUon, synthetic or silk tliread can be used according to your purpose.
Normally left twist thread is used, but right twist thread is recommended
in the left-hand needle for perfect stitching.
INSERTING AND REMOVING BOBBINS
Raise the neetlle bar to its highest iK)int and push open the slide plates
(1). Pull up the latches (2) of the bobbin cases and lift the bobbins (3) out
of the bobbin cases.
To insert a full bobbin in the bobbin case, hold it between thumb and
index finger of your hand. Place the bobbin on the center post of the bobbin
case and push down the latch (2). Be sure that the thread draws out from
the bobbin from left to right.
Pull the thread into the slot (4) and between the bobbin ca.se ojjener (5)
and the projection (6) and under the tension spring (7). Draw out about
5 mm of the thread on the needle plate and close the slide plate leaving a
sufficient space for passage of the thread.
WINDING BOBBINS AND ITS ADJUSTMENT
Push a bobbin on the bobbin winder spindle (1) as far as it will go. Pass
the thread from the thread stand downward through the eye in the tension
bracket, then between and around the back of the tension disc, bring the
thread forward toward the bobbin and wind from below in clockwise direction
several times around the bobbin.
Push the bobbin winder lever (3) downward until the wheel (2) contacts
the drive belt and then start the machine.
Fig. 5
Fig. 6
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After the bobbin is filled with thread, release will cause wheel to disengage
from the belt and winding will stop. Cut the thread and remove the bobbin
from the spindle.
Adjustment screw (5) can be turned in or out to increase or decrease the
amount of thread wound on the bobbin.
When fine thread is wound on bobbins, use light tension, it is regulated
by turning the knurled nut (6) on the tension bracket at the rear of the
bobbin winder.
Bobbin can be wound while the machine is sewing.
If the thread does not wind evenly on the bobbin, loosen the screw (4)
in the tension bracket and move the bracket to right or left as may be
required, then tighten the screw.
THREADING THE MACHINE
Raise the needle bar to its highest point.
From the thread stand, lead the thread to the thread guide (1), (A) on
top of the machine, down to the upper guide hole of the thread guide (2),
(B) from right to left. Pass the thread in weaving fashion through the other
two holes in (2), (B) and from right to left over and between the tension
discs (3), (C). Now pull the thread downward from right to left beneath
and around thread controller (4), (D), continue to pull the thread upward
through the fork in the thread controller and against the pressure of the
check spring (5), (E) and through the thread guide (6), (F) pull the thread
upward through the eye in the take-up lever (7), (G) down through the
thread guide (6), (F) again and then through the thread guide (8), (H) and
(9), (I) down through the hole (10), (J) in the needle holder and from inside
to outside through the eye (11), (K) of the needle.
? 28
ltj
Fig. 7
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REGULATING THE THREAD TENSIONS
For ordinary stitching, the tension of the upper and lower threads should
be equal so as to lock both threads in the center of the fabric. If the tension
on either thread is stronger than on the other, imperfect stitching will be the
result.
If the tension on the upper thread is greater than that on the lower thread,
it will be straight along the upper surface of the fabric.
If
the tension on the lower thread is greater than that on the upper thread,
the lower thread will lie straight along the underside of the fabric.
Perfect stitching
Tight tension of needle
thread
Loose tension of needle thread
Fig. 8
A. TENSION OF THE UPPER THREAD
To adjust the tension of the upper (needle) thread, turn the serrated nut
(1) to the right for increasing tension. If you desire to decrease it, turn the
nut to the left.
B. TENSION OF THE BOBBIN THREAD
It is regulated by means of the tension screw (1).
To increase the tension, turn the screw to the right, and to decrease it,
turn the screw to the left by a screw driver.
ADJUSTMENT OF THE PRESSER FOOT PRESSURE
The pressure of the presser foot is regulated by the adjusting screw (1).
To increase the pressure, turn the screw to the right and to decrease it
to the left by ascrew driver.
Fig. 10
Fig. 11
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ADJUSTING THE STITCH LENGTH
The stitch length is changed by pressing
down
the button (D, Fig. 2) in the bed plate
of the machine and by simultaneously turning
the handwheel slowly toward you.
In due course, the plunger will enter into
anotch in the feeding mechanism. Hold the
plunger down and continue to turn the hand-
wheel, either forward or rearward, until the
marking with the desired number of stitches
on the handwheel coincides with the refer
ence mark on the arm. Then release the
plunger.
Numerals on pulley
show number of
stitch per inch
Stitch length
(m/m)
REVERSE STITCH
To do tacking for the purpose of locking the ends of seams, rapidly
depress and release the lever (E, Fig. 2).
When reversing feed of the machine, keep the lever (E) depressed as long
as required.
For all other forward stitching, the lever remains in up position.
REPLACEMENT OF THE TIMING BELT
1. INSERTING THE BELT
Turn the balance wheel toward you until the take-up lever reaches to its
highest point.
Turn the lower shaft (1) until the arrow mark on the lower shaft bearing
collar (2) meets with another arrow mark on the timing plate (3).
Insert a new timing belt into the belt pulley at this position.
I
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2. REMOVING THE TIMING BELT
Remove the arm top cover (F, Fig. 2) and remove the timing belt from
the belt pulley, loosen the collar set screws (1, Fig. 13).
Loosen the two set screws (G, Fig. 2) for the handwheel and remove the
handwheel adjusting screw (14, Fig. 1), draw out the handwheel from the
arm shaft.
Loosen the arm shaft rear bushing set screw (2, Fig. 13), pull out the
rear bushing (3, Fig. 13) from the arm hole.
In case of the machine with reverse stitch mechanism, draw out the reverse
lever (E, Fig. 2) with its shaft.
Removing or inserting the timing belt is made through the hole drawn out
the rear bushing.
After inserting the belt correctly, replace the rear bushing, screws, the arm
top cover, etc. to their original places. Finally, adjust the timing marks
mentioned in the item No. 1.
ADJUSTING THE HEIGHT OF THE FEED DOG
The maximum height of the feed dog (1) from the surface of the needle
plate (2) is normally 1 mm.
To adjust this height, tilt the machine, turn the handwheel so as to raise
the feed dog to its highest point.
Loosen the set screw (4, Fig. 3) and raise or lower the feed dog as may
be required.
Securely tighten the set screw.
ADJUSTING THE TIMING OF THE NEEDLE PLATE, NEEDLE & FEEDER
1. THE POSITION OF THE FEEDER AGAINST THE NEEDLE PLATE
Adjust the feed motion to the maximum and loosen the screw (4, Fig. 12).
Set the position of the feeder so that both clearances A and B (Fig. 15) are
equal before starting feed motion and after finishing the feed. Securely tighten
the screw.
r1
mm
Fig. 14
Fig. 15
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2. THE POSITION OF THE NEEDLE AND NEEDLE HOLE OF THE
FEEDER
To adjust this, turn the handwheel to raise the needle bar to its highest
point and put correct needles.
Turning the hand wheel to lower slowly the needle bar, check whether
the needle descends to the center of the needle hole of the feeder or not.
If the needle does not enter into the center of the hole, remove the side
plate (H, Fig. 2) and loosen the screw (1, Fig. 16) through the window of
the arm.
Holding the bottom of the needle bar rock frame (I, Fig. 17), move it as
may be required to get the correct position to the center of the needle hole
of the feeder.
Then, tighten the screw and replace the side plate.
ADJUSTING THE HEIGHT OF THE NEEDLE BAR
1. When the needle bar is at its highest point, normally the measurement
between the surface of the needle plate and the upper end of the needle
eye is 22.2 mm.
To adjust this, loosen the screw (2, Fig. 17) and move the setting position
of the needle bar and the needle bar connecting stud (3, Fig. 17) to get the
correct position. After this, tighten the set screw.
2. There, is another method for this adjustment by setting the needle bar
to its lowest point.
The normal position, in this case, is 4.1 mm approximately from the hook
point to the upper end of the needle eye.
NOTE: These measurements are approximate standard, accordingly, following finaladjustments
are recommended.
Bb
Fig. 16
Fig. 17
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TIMING BETWEEN THE HOOK AND NEEDLE
After setting the needle bar height as stated 1. or 2., confirm as under.
Set the stitch length to 0, turn the balance wheel to lower the needle bar to
its lowest point turn the wheel toward you, and when the needle raises 2.1 mm
from the lowest point of its travel, normally the hook point is at the center
of the needle, and the measurement between the hook point and the upper
end of the needle eye should be 2 mm, further the clearance between the
hook point and the needle hollow should be 0.05 to 0.2 mm.
If they are not measured as above, adjustments are made as follows:
2.1mm
Fig. 18
TIMING ADJUSTMENT
Loosen the two set screws {1, Fig. 19A), set the position of the large
gear (2, Fig, 19A) to the center of the small gear (5, Fig. 3) and tighten the
two set screws securely.
Loosen the screw (6, Fig. 3) on the small gear, move the hook and set
the proper timing. Then, tighten the screws securely.
For model LSW-27BLK
Loosen the two set screws (1)—Fig. 19A—, move the large drive gear (2)
to right or left and set the proper timing. Then, tighten the screws securely.
Fig. 19A
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For model LTW-27BK
Loosen the three set screws (1)—Fig. 19B—, move the hook and set the
proper timing. Then, tighten the screws securely.
Fig. 19B
ADJUSTING THE CLEARANCE
Loosen the set screw (3, Fig. 3) and (4), move the hook saddle (5) to
the right or left to get the correct clearance and tighten the screw. Be sure
to use perfect needles.
RELATIVE POSITION BETWEEN BOBBIN CASE AND OPENER
Loosen the screw (1), turn the balance wheel until the opener (2) is
located at the extreme right hand position of its travel.
In this position, adjust it so that the clearance between the inside edge of
the opener and the tab on the bobbin case holder is about 0.2mm.
After the adjustment, tighten the screw securely.
Fig. 20
10
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11
ADJUSTING THE HEIGHT OF THE PRESSER FOOT
Loosen sufficiently the adjusting screw (1, Fig. 11), raise the presser bar
lifter and loosen the screw (4, Fig. 17).
Move the presser foot up or down as may be required, and tighten the
screws securely.
FINE ADJUSTMENT OF THE NEEDLE FEED
Ordinarily, the feed motion of the lower feed synchronizes with that of
the needle feed.
If, when the motion does not synchronize, or increasing or decreasing that
of the needle feed according to the sewing conditions, the following adjust
ments are offered.
Loosen the nut (5, Fig, 12) and bring (6, Fig. 12) close to the feed driving
rock shaft (7, Fig. 12) for more feed momentum or keep away from for less
momentum. Tighten the nut firmly.
CHANGING THE NEEDLE GAUGE
Remove the needle, presser foot, needle clamp, needle plate and feed dog
in this order. The needle clamp is a screwed type that is removed with a
pair of pliers.
Put the desired needle clamp in place by screwing it tight into the needle
bar.
Loosen the needle bar connecting stud screw (2, Fig. 17) and turn the
needle bar to correct the direction of the needle clamp.
Set the correct timing between the hook and the needle.
Put the feeder, needle plate and presser foot in this order securely.
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SPECIAL INSTRRCTIONS FOR MODEL LTW-27BK AND LSW-27BLK
Models LTW-27BK and LSW-27BLK are specially designed as two-needle
angular seam sewing machines. Model LTW-27BK employs standard size
bobbins, while model LSWr27BLK uses large-capacity bobbins. Both models
are equipped with devices to prevent the presence of lower thread loops when
sewing seams with acute (less than 90°) andles.
NEEDLE BAR STOP MECHANISM
Pushing the needle bar change over lever (1)—Fig. 21—to either position
"L" or "R" will selectively suspend the reciprocating movement of either
one of the two individual needle bars.
Basically, there are two functions to this mechanism, one which causes the
needle bars to operate and stop, and the other which switches from one needle
bar to the other.
Fig, 21
12
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13
A) NEEDLE BAR STOPPING AND OPERATING MECHANISM
The two needle bars individually and jointly, with the components as
sembled to their insides, cooperate with the needle bar connecting stud (Fig.
22) to accomplish the stopping and the operation.
The positioning of the needle bar at their upper ends relative to the
needle bar connecting stud is done by means of split stop rings (2) which are
inserted into grooves (1) near the top ends of the needle bars, as well as with
the set screws of the needle bar position guides.
At their opposite ends the needle bars are locked to the needle bar con
necting stud by means of three special high-strength steel balls expanded by
a mechanism inside the needle bars beyond the diameters of the bars. Con
sequently, when
positioned as described above and as pictured on Fig. 22, the
needle bars move up and down with the needle bar connecting stud and are,
what may best be described as "operational".
Needle
0.
Needle
bar
connecting
stud
Needle bar
Fig. 22
Fig. 23A Fig. 23B
Operating mode Non-operating mode
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The mechanism disposed within the needle bar is detailed on Fig. 23A
which shows a needle bar in the operational state, while Fig. 23B shows a
needle bar in stopped position. The force of spring (1) pushes plunger (2) and
adjusting nut (3) against cone (4) which in turn forces three steel balls (5)
outwardly beyond the diameter of the needle bar and against the countersink
at the bottom end of the needle bar connecting stud (6). At the same time
triangular prism (18) is allowing three steel balls (7) to recede below the dia
meter of the needle bar. Consequently, the movement of the needle bar
connecting stud will cause the needle bar to reciprocate.
When stopping a needle bar by moving the change over lever (1) (Fig.
21) into either the "L" or "R" positions, the mechanism locates needle bar
selector block (8)—Fig. 23B—directly above the respective rod end (9). This
rod end of the reciprocating needle bar nowcontacts the selector block causing
the rod to move downward inside the needle bar causing cams (10and 11) to
likewise move downward. This allows upper balls (19A) to recede below the
diameter of the needle bar while at the same time forcing lower balls (19B)
outwardly beyond the diameter of the needle bars. Lower balls (19B) are now
forced against the tapered mouth (14) of the needle bar bushing (13) and will
stop the downward movement of the needle bar. While needle bar position
guide (15) contacts the bottom of the upper end of the needle bar rock frame,
thereby locking the needle bar tightly into place. At the same time the retracted
upper balls (1*9A) do no longer lock the needle bar against the underside of
the needle bar connecting stud (6) and so allow the latter to glide along the
needle bar.
PREVENTION OF NEEDLE BAR ROTATION
Needle bar position guide (1) in conjunction with the bifurcated needle bar
position bracket (3), attached to needle bar connecting stud (2)—Fig. 24—in
conjunction with needle bar position guide plate (4) keep the needle bar from
rotating. In the operating mode, bracket (3) serves this purpose, while when
a needle bar is stopped the channels embossed into the guide plate (4) prevent
rotation.
n
Fig. 24
14
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15
VERTICAL ADJUSTMENT OF NEEDLE BAR POSITION
The exact vertical position of the needle bars is important for their
trouble-free engagement and disengagement, respectively, since their positions
are fixed within the needle bar rock frame (20)—Fig. 23. For the purpose of
making the required fine adjustment of the needle bar position, and eccentric
bushing (5)—Fig. 24—is provided in needle bar connecting link (6).
B) NEEDLE BAR RELEASE MECHANISM
When the needle bar change over lever (1)—Fig. 21—is set to either "L"
or "R" position, the rod end (9) of the selected needle bar, when same is in
its highest position, will contact the underside of selector block (8) causing
said needle bar to become disengaged from its driving mechanism.
OPERATION OF THE NEEDLE BAR CHANGE OVER FRAME
Shifting the needle bar change over lever—Fig. 21—to "R" will cause
the needle bar change over frame to move in direction of the arrow (Fig. 25).
The needle bar change over frame connection, when the needle bar lowers
and was disengaged, is fixed to their normal position as Fig. 25B. At the
same time, the needle bar stops when same reached in its next highest position.
When disengaing the needle bar stop pushing the lever release (4)—Fig.
21—,
the needle bar change over frame and the needle bar change over frame
connection return to their first position. Thereby, the slide block for needle
stop separates from the needle bar stopping stud and returns to their first
position.
Then, the needle bar connecting stud incorporates with the needle bar in
its highest position and becomes normal twin needle operation.
W
Fig. 25
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SPECIALLY-DESIGNED ROTATING HOOKS FOR ANGULAR
SEAM SEWING
The rotating hooks for models LTW-27BK and LSW-27BLK have been
developed specifically for these machines and are provided with specific clear
ances (1)—Fig. 26—to allow the most effective transit of the sewing thread.
Furthermore, the hook for model LSW-27BLK with its larger bobbin provides
for much increased thread volume.
Also, should the machine be stopped at that point of its stitching cycle
when the upper (needle) thread is about to pass over the hook, the shape of
thread guard (2) will allow unhampered passage of the thread.
The cap-type design of the bobbin case assures smooth thread handling.
The horn-likeextension(4)of the
hook gib retains the upper thread temporarily
taking up the slack, while it courses around the hook.
Thus looping is prevented, particularly when heavy threads or those lacking
smoothness are employed.
Automatic lubrication of the moving parts of the hooks allows the main
tenance of adequate sewing speeds without sacrificing their useful service
life.
Fig. 26
METHOD OF PREVENTING LOOPING OF THE LOWER (BOBBIN) THREAD
When sewing angular seams—particularly acute angles—with machines
fitted with conventional types of rotary hooks, the appearance of large loops of
20 mm
Bobbin
Fig. 27
B
KIO-H
mm
T, • ^
16
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17
the lower thread can be noticed at the underside of the work. This is caused
by the transport of the material around the sewn corner, while the one raised
needle bar is at rest.
The rotary hooks of models LTW-27BK and LSW-27BLK are equipped
with devices which prevent the looping of the lower thread by withdrawing
by means of springs any excess of thread.
Fig. 27A shows the method of threading of the bobbin case of model
LSW-27BLK. Fig. 27B shows the position of thread take-up spring (1) ready
to pick up any excess of thread for the prevention of loops. Also note that
the dotted outline of the thread take-up spring (lA) which shows same in a
rest position prior to pulling back excess thread. As can be seen froni this
figure, spring (1) travels a distance to where its eye coincides with the thread
guide hole in retainer (2).
When in this position, further demand for bobbin thread is then pulled
out from under bobbin case tension spring (3). The function and effectiveness
of spring (1) is such
that slack thread loop containing as much as 20 mm
(25/32'') of thread can be absorbed.
THREAD CONTROLLER SPRINGS
There are two separate and individual thread controller springs—one for
each of the two upper (needle) threads—installed in the machines.
Rg. 28
When sewing angular seams with either one of the two needle bars
stopped, upper thread is not drawn out at an equal rate for both needle bars.
Consequently, two thread controller springs are required to cope with this
condition. These springs can be adjusted individually.
A) Adjusting the rear thread controller spring
Loosen set screw (2), turn thread controller spring stop (3) to the right
for more action ; for less action turn stop (3) to the left and tighten set screw
(2).
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