JUKI LH-4128-7 Engineer'S Manual Download

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Direct-drive, High Speed, 2-Needle, Needle-feed, Lockstitch Machine

LH-4128

LH-4128-7/4168-7/4188-7

40038257

No.E367-03

ENGINEER’S MANUAL

Direct-drive, High Speed, 2-Needle, Needle-feed, Lockstitch Machine
with Automatic Thread Trimmer

Summary of Contents for LH-4128-7

Page 1: ...High Speed 2 Needle Needle feed Lockstitch Machine LH 4128 LH 4128 7 4168 7 4188 7 40038257 No E367 03 ENGINEER S MANUAL Direct drive High Speed 2 Needle Needle feed Lockstitch Machine with Automatic Thread Trimmer ...

Page 2: ... the relevant Instruction Manual and Parts List together with this Engineer s Manual and the manual of SC 910 when carrying out the maintenance of these machines In addition for the motor for the sewing machine with thread trimmer refer to the separate Instruction Manual or Engineer s Manual for the motor And for the control panel refer to the Instruction Manual for the control panel This Engineer...

Page 3: ...en the throat plate and the bobbin case stopper 20 6 Relation between the main shaft and the lower shaft 22 7 Lubrication 24 1 Lubrication system 24 2 How to clean the filter section 24 3 Hook oil amount 24 4 Oil in the feed box 26 5 Replacement of the hook shaft oil wick 26 6 Replenishing grease to the specified places for LH 4168 7 LH 4188 7 only 28 8 Forward and reverse stitch pitches 32 9 Adju...

Page 4: ... 17 Thread take up lever guide position 54 6 Separately driven needle changeover switch for LH 4168 7 LH 4188 7 only 56 7 Gauge replacing procedure 57 8 Needle feed bottom feed changeover 59 9 Replacing the timing belt 62 10 Installation removal of the needle bar rocking base 64 11 Sewing specification 66 12 List of gauge components 67 1 LH 4128 67 2 LH 4128F 69 3 LH 4128 7 70 4 LH 4168 7 71 5 LH ...

Page 5: ... Control box used SC910A AA Caution 3 15 External dimensions Width 615mm Heigh 420mm Depth 267mm with AK125 16 Weight of head 65kg LH 4168 7 AK125 17 Power consumption 650VA 18 Temperature 5 C to 35 C Humidity 35 to 85 no condensation 19 Rated voltage 10 50 60Hz 20 Approx 83dB A Shipping voltage classification 3 100 to 120V 4 200 to 240V 1 Specifications Caution 1 4 mm only in the case of Specific...

Page 6: ...l Bobbin winder changeover switch Knee patch Thread stand LH 4168 7 LH 4188 7 only Power switch Oil supply opening Thread take up cover Hand switch Reverse feed control lever Finger guard Operation panel Hand lifter lever Thread tension controller Control box ...

Page 7: ...ications F Specification for foundation S Specification for medium heavy weight materials G Jeans specification for heavy weight materials 13 Classification for attachment application Standard throat plate standard face plate and standard cloth presser Taping throat plate and taping face plate Presser with a guide 14 to 18 Classification of presser lifter Space Not provided AK125 Auto lifter Pedal...

Page 8: ...lassification for the head specifications S Semi dry head 20 Place of distination A Standard 21 Accessoried type A Standard 8 Classification for the sewing specification S Specification for medium heavy weight materials G Jeans specification for heavy weight materials 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 L H 4 1 F A 7 W B A A Model 4188S 7 9 Standard marked by 10 Classification fo...

Page 9: ...er lines of the oil tank 4 Special notes for safe operation Upper engraved maker line Lower engraved maker line 3 When the sewing machine is operated for the first time or when it is reused after a long time of storage running in operation shall be carried out at a speed of 3 000rpm or below At that time a few drops of machine oil shall be applied to the section indicated by the arrow Caution Neve...

Page 10: ...thread winding direction is indicated by the arrow o LH 4128 Latch hook o LH 4168 7 Hook with a thread trimmer and an separately o LH 4128 7 Latch hook with a thread trimmer driven needle o LH 4188 7 Hook with a thread trimmer and an separately driven needle 6 When synthetic threads are used the thread guide arm asm for the thread stand asm if the thread flaps during sewing Thread guide arm asm Th...

Page 11: ... 7 MEMO ...

Page 12: ... needle bar is in the lowest dead point o Feed amount Minimum o LH 4128 LH 4128 7 o LH 4168 7 LH 4188 7 5 Standard adjustment 1 Needle bar and feed dog Standard Adjustment Top surface of the throat plate Top surface of the throat plate 13 5 0 1mm 14 1 0 1mm ...

Page 13: ...Caution 1 Distance from needle bar to presser bar should be the distance provided between the bottom end of the presser bar and the bottom end of presser bar lower bushing 2 After the adjustment the needle entry point in the needle slot in the feed dog may change Adjustment Procedure Results of Improper Adjustment When the stitch length is maximized the feed dog will come in contact with the throa...

Page 14: ...nt Minimum o When the feed dog is in the hightest position of its stroke it should rise 1 0 1mm from the top surface of the throat plate Top surface of the throat plate 1 0 1mm Feed base Standard Adjustment Feed base Feed rocker shft Clearance Clearance C A B LH 4188 7 Horizontal LH 4128 4128 7 4168 7 ...

Page 15: ...djust the feed dog to 1 0 1mm from the upper face of the throat plate After adjustments tighten the setscrew Caution 1 After adjustments the needle location may be changed in relation to the hole of the feed dog o Feed dog gradient 1 Remove the cap of the bed side face and loosen the feed bar shaft setscrew Turn the roulette section to adjust the gradient Standard adjustment o LH 4128 LH 4128 7 LH...

Page 16: ...t o Feed amount Minimum o LH 4128 o LH 4128 7 o LH 4168 7 o LH 4188 7 Standard Adjustment Meets with the upper engraved marker line Maker lines engraved on the needle bar Needle bar connection Maker lines engraved on the needle bar Coinciding with the uppermost engraved marker line ...

Page 17: ...lower end face of the needle bar rocking base and tighten the tightening screw at a tightening torque of 5 9N m 60kgf cm Caution 1 After the adjustment the needle entry point in the needle slot in the feed dog may change 2 When tightening the setscrew make sure not to shift the needle throwing drive arm in the direction of the arrow When the DPX17 is used While the DPX17 is used the second engrave...

Page 18: ...ons o Needle bar should be in the lowest dead point o Feed amount 2 5mm B C D 1 2mm 2 2mm Dimension for reference Needle clamp height at the lower dead point of the needle bar Throat plate mounting surface A A o Spec S F o Spec G LH 4128 4128 7 LH 4168 7 Spec S LH 4168 7 Spec G LH 4188 7 Dimension A 15 1 0 15mm 15 8 0 15mm 14 6 0 15mm 15 2 0 15mm o LH 4128 o LH 4128 7 Feed bar o LH 4168 7 o LH 418...

Page 19: ... arm After adjustments tighten the feed bar arm tightening screw Caution 1 Needle clamp can be turned in the clearance provided between screw and the rightmost and leftmost edges on the slot in the needle bar o Stitch skipping and thread breakage will be caused o Poorly tensed seam will result o When the feed dog has elongated needle slots 2 2mm x 3 2mm the needle thread will be loosened if the ne...

Page 20: ...type it should be set at 2mm 2 Timing between the needle and the hook Standard Adjustment 0 to 0 05mm Blade point of the hook Needle guard of the hook 0 03 to 0 1mm o LH 4128 o LH 4168 7 LH 4128 7 LH 4188 7 Application A mm B mm S G F 2 2 1 2 B Blade point Center of the needle aligns with the blade point of the hook Lift of the needle bar when the lower maker line on the needle bar meets the botto...

Page 21: ... of 0 to 0 05mm is secured between the needle and the blade point of the hook and that the needle guard attains the specified effective amount of 0 03 to 0 1mm Then tighten the setscrews and to fasten the hook shaft base 5 Install the connector link by means of the hinged screw At that time keep the moving knife driving arms and pressed against the moving knife driving arm stopper respectively and...

Page 22: ... marker line of the 3 serial engraved marking the amount of opening for the inner hook stop and the throat plate rib becomes 0 3mm standard adjusting value Backward travel end Press the bobbin case stopper against the throat plate ribs 0 3 to 0 4mm o LH 4188 7 A 4 Standard adjusting position for the inner hook guide arm shaft Standard Adjustment Setscrew Slot ...

Page 23: ...tscrew of the inner hook guide and adjust the clearance to 0 3 to 0 4 mm between the inner hook guide and the embossed part A of the bobbin case After adjustments tighten the setscrew When it stays on the side of the shorter engraved marking o Towel face stitches loosened stitches or thread breakage will result When it is adjusted faster than the longer engraved marking o The bobbin case may break...

Page 24: ...ok driving shaft upper bushing thrust plate F 4 1 4 10109809 Hook driving shaft upper bushing thrust plate B 5 1 5 10112506 Hook driving shaft upper bushing thrust plate G 6 1 6 10112605 Hook driving shaft upper bushing thrust plate H 7 1 7 10112704 Hook driving shaft upper bushing thrust plate K 8 1 8 22614002 Hook driving shaft upper bushing spacer A A 1 9 22614101 Hook driving shaft upper bushi...

Page 25: ...machine the bottom section of the hook shaft is sealed with gaskets Therefore if any air pressure is exerted loosen the bottom screws 4 pcs used to fix the hook shaft base from the bottom Then tighten the setscrews 3 pcs of the hook shaft screw gear under the condition of no air pressure If the clearance provided between the throat plate and the bobbin case stopper is larger than the specified val...

Page 26: ...he main shaft and the lower shaft Standard Adjustment Worker side LH 4188 7 only Lower dead point of the needle bar 180 Make a reverse rotation by 13 6mm 167 5 LH 4128 7 LH 4168 7 Condition that the sewing machine is laid down ...

Page 27: ...the position where the needle bar does not rock in the feeding direction even though the hand wheel is fixed the lower shaft is turned and the reverse feed lever is pushed At that time the engraved marking dot of the lower shaft almost coincides with the engraved marking line of the sprocket LH 4128 7 LH 4168 7 5 Fasten the first screw of the sprocket and then the second screw The third screw is u...

Page 28: ...ng there shall be generation of oil splashes in 5 seconds oil splashes Oil amout decreases Oil amount increases A sheet of paper Hook Upper engraved maker line Lower engraved maker line 1 Lubrication system 2 How to clean the filter section 22mm Circulation tube Oil tank Bottom cover Plunger ...

Page 29: ... clean the filter section Plunger filter 1 and Plunger filter 2 1 Loosen the setscrew of the lubrication tube holder for removal from the bed 2 Loosen the pipe stopper to take out the tube and the joint 3 Recover the initial state after the removal of dust attached to the net area of the joint 4 For the urethane filter and the circulation filter remove thread chips cloth and dust from these filter...

Page 30: ... 26 1 2 3 4 4 Oil in the feed box Standard Adjustment 5 Replacement of the hook shaft oil wick ...

Page 31: ...3 places of the hook gib and remove hook gib 2 Remove inner hook 3 Loosen oil plug with the L shaped screwdriver Part No B9101490000 and remove it 4 Draw out the oil wick that inserted in the oil plug and replace it with a new one Refer to 4 for the insertion depth Part No of oil wick 11015906 Caution When strongly pressing oil wick it may be broken Lightly insert it to such an extent that it is n...

Page 32: ... 28 6 Replenishing grease to the specified places for LH 4168 7 LH 4188 7 only 1 Replenishing grease to the needle bar drive cam section Standard Adjustment ...

Page 33: ...ration marked with in Step 1 described above Caution 1 After replenishing grease call memory switch No 118 set the description to 1 and turn OFF the power Otherwise error No E220 or error No E221 is displayed again 2 For replenishing grease to the specified places below use JUKI GREASE A TUBE Part No 40006323 or JUKI GREASE B TUBE Part No 40013640 supplied as ac cessories If grease other than the ...

Page 34: ... 30 2 Center link section Standard Adjustment ...

Page 35: ...pe through the rubber cap hole located at the top surface of the face section and connect it with nipple left Then turn the supplied screw to the joint and fill the joint with JUKI grease B 5 Return the face plate rubber cap and top face cover to their home places Caution 1 To confirm the amount of replenishing at all grease re plenishing sections is performed by confirming that grease protrudes f...

Page 36: ...tandard Adjustment Conditions o When the stitch dial is set at 3 the difference in the stitch length between the normal feed stitching and reverse feed stitching should be 0 2mm or less Feed regulator base Feed regulator base Feed regulator base rod ...

Page 37: ...djust so that a difference in stitch length becomes 0 2mm or less between the normal feed stitching and the reverse feed stitching Fasten the setscrews 2 pcs of the feed regulator to base pin o The stitch length for reverse feed stitching will be different from that for the normal feed stitching Adjustment Procedure Results of Improper Adjustment ...

Page 38: ...e up stop position of the sewing machine 2 Needle down stop position of the sewing machine 9 Adjusting the needle stop position Standard Adjustment F E B A D C Red maker dot 0 to 3mm Upper surface of the feed dog ...

Page 39: ...OWN position turn the power OFF and loosen the screw within the range of the oblong hole The needle stop motion is fastened if the screw is moved in the direction of E and delayed if it is moved in F Caution Do not operate the machine with screw loosened Just loosen the screw and do not remove it o If the needle up stop position of the sewing machine is not properly adjusted thread trimming failur...

Page 40: ... 36 Presser lifting plate 10 Disc release changeover for lap lifter Standard Adjustment There is a hexagon socket head cap screw behind the rubber cap that has been removed ...

Page 41: ... interlocking the thread tension release 1 Remove the rubber cap 2 Mount and fix the hexagon socket head cap screw supplied Caution 1 Thread slacks when turning cloth at the corner stitch ing and sewing trouble of thread tension release may occur 2 When the wiper is not used at the time of thread trim ming needle thread may be drawn out when removing cloth 3 When removing the hexagon socket head c...

Page 42: ... 38 11 Needle bar stroke adjustment for LH 4168 7 LH 4188 7 only Standard Adjustment Stroke small Stroke large Needle drive Needle stop Model Dimension A mm LH 4168 7 31 6 0 2mm LH 4188 7 32 6 0 2mm 1mm ...

Page 43: ...e same time Therefore adjust the as per 5 1 3 Needle bar height 4 Based on the amount of needle stopper screw in adjust the needle bar stroke to 0 0 2mm in the position of needle stop Loosen the nut and adjust the amount of screw in of the needle stopper Since then tighten the nut again 5 Install the changeover solenoid by means of eight screws Con firm that the knuckle has a play in the revolving...

Page 44: ... 40 12 Thread trimming device 1 Moving knife position 2 Adjusting the height of the counter knife Standard Adjustment C B C A A ...

Page 45: ... the height of the counter knife 1 Align the counter knife base with the plane C of the counter knife and tighten the setscrew 2 Loosen the setscrew of the counter knife base and change its height with the eccentric pin to adjust the pressure of the counter knife Adjustment Procedure Results of Improper Adjustment o If the counter knife pressure is too high this can be a cause of failure in return...

Page 46: ... 42 3 Adjusting the thread presser spring A Standard Adjustment ...

Page 47: ... and loosen setscrew with a hexagonal wrench key of 1 5 mm 2 Adjust the thread presser spring by rod in the direction of arrow mark A and fix it with setscrew Caution Clamp trouble occurs even when the thread presser spring pressure is excessive or insufficient So be careful Adjustment Procedure Results of Improper Adjustment ...

Page 48: ...ion of the thread trimming cam and the thread trimming timing B side Standard Adjustment 5 Clearance between the thread trimming cam and the thread loosening arm A Enlarged Part A in the top right diagram B side A ...

Page 49: ...engraved marker dot red of the hand wheel exactly coincides with the arm s engraved marker dot o Thread trimmer cam position check 1 In the state that the thread trimmer drive arm stopper keeps contact with the knife drive stopper turn the hand wheel so that the groove state straight section of the thread trimmer cam comes to the position of the cam roller 2 Confirm that the cam roller does not in...

Page 50: ... 46 6 Adjustment of thread tension release Standard Adjustment Clearance 0 ...

Page 51: ...n the disc rise pin and the disc rise plate 2 If presence of some play is perceived loosen the nut and shift the wire to the left side so that the clearance can be adjusted to zero between the disc rise pin and the disc rise plate Adjustment Procedure Results of Improper Adjustment ...

Page 52: ...e reverse feed solenoid and the plunger rubber washer when the reverse feed control lever is pressed sown until it will not go further 13 Wiper components Standard Adjustment 14 Reverse solenoid position Standard Adjustment Wiper length Wiper position Wiper length 2 to 3mm Wiper position 1 1 0 2mm 0 5 to 1mm ...

Page 53: ...es closest to the needle clamp If the clearance provided between the plunger radial plate and the reverse stitching solenoid is larger than the specified value o The attraction of the magnet will be decreased In this case the machine fails to start reverse feed stitching If there is no clearance provided between the plunger radial plate and the reverse stitching magnet o The stitch length for reve...

Page 54: ...trol le ver until the lever is aligned with the reverse feed link a clearance of 0 5 0 2 mm should be provided between the reverse feed control lever and the back lever stopper 15 Initial position of the reverse feed control lever Standard Adjustment Lightly press the reverse feed control lever 0 5 0 2 m m Align ...

Page 55: ...s time a clearance of 0 5 0 2mm should be provided between reverse feed control lever and back lever stopper 3 If the clearance deviates from the range of 0 5 0 2mm loosen the screw and make the reverse feed lever coincide with the reverse feed link Adjust the clearance between the reverse feed lever and the back lever stopper to 0 5 0 2mm and tighten the screw Caution When the screw in the feed a...

Page 56: ...ifter be sure to set the function to lift the presser foot after thread trimming function setting No 055 of the control box inoperative 0 off 2 Assembling the knee patch plate asm Condition Play in the knee patch plate hori zontal shaft in the axial direc tion Approx 0 2 mm Amount of play End face Viewed from A A 1 Assembling the knee lifter detection sensor plate asm The knee patch plate and othe...

Page 57: ...nd the two setscrews that are temporarily fixed on the bottom cover 2 Attach knee lifter detection sensor plate asm with screw at a position where a 0 5 to 1 0 mm clearance is provided between knee lifter detection sensor and the periphery of knee lifter detection seat asm 2 Assembling the knee patch plate asm 1 Apply the knee lifter working shaft to the boss end plane of the bottom cover and fast...

Page 58: ... Adjusting the knee lifter detection seat asm The knee patch plate and other parts are excluded from the above illustration LED Align end surfaces Magnet LED Detecting section 17 Thread take up lever guide position Standard Adjustment Model Dimension A mm LH 4128 4128 7 15 5 0 5mm LH 4168 7 13 0 0 5mm LH 4188 7 5 0 0 5mm A ...

Page 59: ...Turn the knee lifter sensor seat asm in the direction of the arrow and secure it with the setscrew where the LED of the knee lifter sensor begins to light At that time align the end face of the sensor seat asm with that of the knee lifter sensor 4 Check that the LED goes up when knee patch plate is released Caution The machine has been adjusted so that the knee lifter actuation is detected when th...

Page 60: ...ial set value Normal mode manual teaching mode When the sewing comes to the corner section press left hand right hand needle changeover switch and teaching switch Sew the corner in a single needle state lift the presser foot turn the cloth and sew the corner of return It is not necessary for the operator to perform the release at the time of return since the release of single needle after this wor...

Page 61: ...e needle and the hook 7 Let the pipe guide stay in the position where the pipe layout can be made optimal Then tighten the setscrew 7 Gauge replacing procedure 1 How to remove the gauge 1 Turn OFF the power switch 2 Remove the slide plate needle needle clamp presser foot throat plate and feed dog In the case of a thread trimming machine provided with a wiper refer to the table of 5 13 Wiper compon...

Page 62: ... dog and tighten the nut Needle hole in the feed dog Needle Clearance Clearance 13 In the case of the thread trimmer tighten four setscrews of the connector link asm while the knife driving arm is pressed against the stopper Caution 1 When attaching feed fog confirm that it is equidistantly spaced in the feed dog slot in throat plate with respect to the lateral direction Also confirm that the need...

Page 63: ... plate should be replaced with the bottom feed parts 3 For needle and feed synchronism timing adjust ments loosen the second setscrew of the bottom sprocket and then loosen the first setscrew after it has been moved to the position as illustrated In this state remove the first setscrew Turn the hand wheel until the position of the third setscrew is secured At that time confirm that the engraved ma...

Page 64: ...that the needle settles in the center of feed dog needle hole For adjustments loosen nut shift needle throwing adjusting screw in the direction of the arrow and regularly tighten nut 3 Loosen the setscrew of the sprocket and turn the pulley by 180 so that engraved marker of the lower shaft can coincide with the engraved marker line When coincidence is secured tighten the setscrew Caution 1 Move th...

Page 65: ... 61 MEMO ...

Page 66: ... 62 9 Replacing the timing belt Clearance check required Feed control base butterfly type S No11 M 004 0 g m W 015 0 mm R S 0224 mm TENSION 85 1N Belt tension gauge Belt tension gauge ...

Page 67: ...s positioned in parallel to the upper plane of the bed and that the first screw of the lower sprocket is positioned on the worker side Refer to 5 6 Relation between the main shaft and the lower shaft 4 Hook the feed adjust spring and mount the reverse feed solenoid Since then mount the reverse feed solenoid lever and the reverse feed arm Refer to 5 14 and 15 5 Install the oil tank At that time be ...

Page 68: ... 64 10 Installation removal of the needle bar rocking base B A ...

Page 69: ...mpletion of fixing confirm without fail that needle bar rocking base is free from rattling in Direction A right and left Also confirm that there is no torque in rocking Direction B 5 Moving the needle bar up and down tighten needle driving arm connecting screw where the right and left positioning of needle driving arm settles in natural position Screw tightening torque 5 9N m 60kgf cm If the screw...

Page 70: ...62005 D3129555D00 Wire diameter Wire diameter Wire diameter 1 0 mm 1 2 mm 0 8 mm Thread tension spring No 1 Part No Part No Part No 22945505 22945505 22945505 Needle standard DPx5 14 DPx5 21 DPx5 10 MDP500B1400 MDP500B2100 MDP500B1000 DPx17 14 DPx17 21 DPx17 10 MDP170B1400 MDP170B2100 MDP170B1000 Caution 1 Caution 1 When replacing the needle for changing the sewing specification adjust the needle ...

Page 71: ...0025795 40025811 Q 1 25 4 22626402 40062258 22631808 40025796 40025812 R 1 1 8 28 6 22626501 22631907 40025797 40025813 S 1 1 4 31 8 22626600 22632004 40025798 40025814 T 1 3 8 34 9 22626709 22632103 40025799 40025815 U 1 1 2 38 1 22626808 22632202 40025800 40025816 S v v v Stitch spec Lowerfeed v v G v v ø1 9 3 2mm 2 2mm Needle gauge size Feed dog Lower feed Sliding plate asm Left Sliding plate a...

Page 72: ... 40026041 10148351 22640957 22817050 W 7 16 11 1 40026043 10148450 22641054 40033941 L 1 2 12 7 40026045 10148559 22641252 22817159 10392751 M 5 8 15 9 40026047 10148658 22641351 40033945 N 3 4 19 1 40026049 10148757 22641450 40033947 10393056 P 7 8 22 2 40026051 10148856 22641658 40033949 22844450 Q 1 25 4 40026053 10148955 22641757 40033951 22844559 R 1 1 8 28 6 40026055 10149052 22641856 400339...

Page 73: ...47358 G 9 32 7 1 22625602 22628507 40033567 40035887 22627657 22647457 H 5 16 7 9 22625701 22928606 40033568 40035888 22627756 22647556 ø1 4 1 4mm Needle gauge size Neeld clamp asm Sliding plate asm Left Sliding plate asm Right Sliding plate asm Front inch mm Part No Part No Part No Part No Part No B 1 8 3 2 40026027 D 3 16 4 8 40026031 E 7 32 5 6 40026033 F 1 4 6 4 40026035 G 9 32 7 1 40026037 H ...

Page 74: ...25503 40061282 40025828 40025842 22641757 40033951 R 1 1 8 28 6 40025504 40061283 40025829 40025843 22641856 40033953 S 1 1 4 31 8 40025505 40061284 40025830 40025844 22641955 40033955 S v v v G v v ø1 7 2 2mm 3 2mm Stitch spec Spec common ø1 9 2 0mm 2 4mm Option Tip divided Tip divided Code Needle gauge size Needle clamp asm Sliding plate asm Left Sliding plate asm Right Sliding plate asm Front W...

Page 75: ...le clamp asm Right inch mm Part No Part No Part No Part No B 1 8 3 2 40035877 40035878 B1402526BA0A B1402526BA0A C 5 32 4 0 40026063 40026084 B1402526CA0A B1402526CA0A D 3 16 4 8 40026065 40026086 B1402526DALA B1402526DARA E 7 32 5 6 40026067 40026088 10228559 10228567 F 1 4 6 4 40026069 40026090 B1402526FALA B1402526FARA G 9 32 7 1 40026070 40026091 B1402526GALA B1402526GARA H 5 16 7 9 40026072 4...

Page 76: ...2816656 F 1 4 6 4 40025492 40061274 40035892 22640551 22816755 G 9 32 7 1 40025493 40061275 40050010 22640759 22816854 H 5 16 7 9 40025494 40061276 40050011 22640858 22816953 K 3 8 9 5 40025495 40061277 40035893 22640957 22817050 L 1 2 12 7 40025498 40061278 40035894 22641252 22817159 M 5 8 15 9 40025499 40061279 40071912 22641351 40033945 N 3 4 19 1 40025500 40061280 40035895 22641450 40033947 Q ...

Page 77: ...68 7 LH 4188 7 4 40033160 Clamp spring LH 4128 7 LH 4168 7 LH 4188 7 5 SM6850400SP Clamp spring setscrew LH 4128 7 LH 4168 7 LH 4188 7 6 10111508 Thread take up spring LH 4128 7 LH 4168 7 LH 4188 7 7 22653802 Idline revention sheet LH 4128 7 LH 4168 7 8 22819809 Idline revention sheet LH 4188 7 9 B1425526000 Needle clamp setscrew LH 4168 7 LH 4188 7 Hexagon socket 10 SM6030672TP Feed dog setscrew ...

Page 78: ...ake up spring thread take up spring are improper the thread take up spring 1 6 Blade point of the hook has scratches Grind the blade point of the hook 1 7 Periphery of the needle hole in Grind the periphery of the needle hole in the feed plate the feed dog has scratches 1 8 The machine head is not properly Refer to the Instruction Manual 11 How to pass the needle thread threaded 1 9 The needle is ...

Page 79: ...the throat plate to 0 9mm plate is not properly adjusted 3 Puckering frequently occurs 3 1 The needle thread tension is too Minimize the needle thread tension as long as stitches are high neatly finished 3 2 The bobbin thread tension is Minimize the bobbin thread tension as long as stitches are too high neatly finished 3 3 The tension of thread take up Minimize the thread take up spring tension as...

Page 80: ...The needle is too thick for the Replace the needle with one that is thinner by one count thread used 4 5 A heavy eight material is used f stitch skipping is likely to occur particularly when using a spun thread Refer to 2 Needle to hook relation Trouble Case 1 Case 2 Check and Corrective measures Stitch skipping is not likely to occur when H mm is adjusted 2 4 to 2 6mm If H mm is excessively incre...

Page 81: ...ngitudinal position of the moving knife positioned 5 5 Operating range of the thread Adjust the operating range of the thread take up spring take up spring is too small using the thread take up spring stopper 6 Bobbin thread trimming failure 6 1 Top end of the moving knife is 1 A Position of the moving knife Replace the moving knife with a new one positioned too low blade 6 2 The hook is positione...

Page 82: ...p timing is 1 A Position of the red maker dot Properly adjust the needle up stop position of the sewing Slip off the thread at the start of sewing excessively advanced engraved on the handwheel and machine the marker dot engraved on the machine arm when the sewing machine stops with its needle up 8 2 Bobbin thread presser spring fails 2 A Check whether the thread is Adjust the position of the movi...

Page 83: ...thread tension Caution When using a thin thread with a higher count stitch skipping or slip off of the needle thread is likely to occur when the remaining amount of bobbin thread is not enough 8 9 Bobbin thread tension is too low 9 A Extent of idling of the bobbin Increase the bobbin thread tension 8 10 The presser foot rises at the Use the soft start function start of sewing Trouble Case 1 Case 2...

Page 84: ...rly knife is not properly adjusted 9 8 Needle to hook relation is not 8 A The clearance provided between Adjust the clearance provided between the hook and the properly adjusted the hook and the bobbin case bobbin case opener to 0 2mm opener is too large 8 B The clearance provided between Adjust the clearance provided between the bobbin case the bobbin case and the throat tand he throat plate to 0...

Page 85: ... that the wiper spreads the thread properly 11 2 Length of the needle thread 2 A Tension of the tension controller Adjust the tension controller No 1 so that the needle remaining after thread trimming No 1 thread of 35 to 45mm remains after thread trimming is excessive 2 B Timing of the thread trimming action Properly adjust the thread trimming timing 2 C Position of the moving knife Adjust the lo...

Page 86: ... 82 MEMO ...

Page 87: ... depth 25 ø17 through hole 2 x ø3 5 depth 10 3 x ø13 through hole 2 ø3 4 on the bottom surface depth 10 2 x ø3 5 depth 10 V V 1 1 3 pcs Z Z 2 pcs Y Y 2 pcs X X 2 pcs T T Detail drawing of measure 2 1 X X C1 5 to C2 5 For hinge side only Type Helvetica Reg Condensed Thickness 1 5 Thickness 0 8 Thickness 0 5 Thickness 1 5 Y Y JUKI rogo type 15 ...

Page 88: ...MEMO ...

Page 89: ...vironmental management system to promote and conduct the following as the company engages in the research development design sales distribution and maintenance of industrial sewing machines household sewing machines industrial robots etc and in the provision of sales and maintenance services for data entry systems 1 The development of products and engineering processes that are safe to the environ...

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JUKI LH-4128-7, Engineer'S Manual

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