Page 2 - SAFETY INSTRUCTIONS; Indications; DANGER; Safety indications and their meanings; CAUTION
i LH4-B800E ................ This symbol ( ) indicates something that you should be careful of. The picture inside the triangle indi- cates the nature of the caution that must be taken.(For example, the symbol at left means “beware of injury”.) ................ This symbol ( ) indicates something th...
Page 3 - Environmental requirements; Installation
LH4-B800E ii All cords should be secured at least 25 mm away from any moving parts. Furthermore, do not excessivelybend the cords or secure them too firmly with staples,otherwise there is the danger that fire or electric shockscould occur. Install the belt covers to the machine head and motor. If us...
Page 4 - Sewing
iii LH4-B800E This sewing machine should only be used by opera-tors who have received the necessary training in safeuse beforehand. The sewing machine should not be used for any applications other than sewing. Be sure to wear protective goggles when using themachine.If goggles are not worn, there is...
Page 6 - CONTENTS
LH4-B800E CONTENTS 1. MECHANISM DESCRIPTION .......................................... 1-1 1-1. Needle take-up mechanism ............................................... 1-1 1-2. Upper shaft, lower shaft and rotary hook mechanism ....... 1-2 1-3. Needle zigzag mechanism .................................
Page 8 - MECHANISM DESCRIPTION
LH4-B800E 1 - 1 1. MECHANISM DESCRIPTION 1. MECHANISM DESCRIPTION 1-1. Needle take-up mechanism 1. When the machine pulley q is turned in the direction of the arrow, the rotation is transmitted to the thread take-up crank e that is secured to the end of the upper shaft w . 2. The needle bar crank r ...
Page 26 - -1. Lower shaft and idle pulley mechanism
LH4-B800E 2 - 1 2. DISASSEMBLY 2. DISASSEMBLY Remove the two screws q , and then remove the cover w . Loosen the set screw e , and then remove the set screw collar assembly r from the lower shaft t . Loosen the set screw y , and then remove the timing pulley assembly u from the lower shaft t . Loose...
Page 41 - -9. Upper shaft and tension pulley mechanism
LH4-B800E 2 - 16 2. DISASSEMBLY Loosen the screw q , and then remove the pulley assembly w . Remove the screw e , and then remove the synchronizer assembly H80 r from the arm. Remove the two bolts t and the two plain washers y , and then remove the tension pulley assembly u . Remove the screw i and ...
Page 47 - -13. Thread breakage detection mechanism
LH4-B800E 2 - 22 2. DISASSEMBLY Remove the screw q , and then remove the lever stopper w . Remove the screw e , and then remove the lever stopper r . Remove the screw t , and then remove the balancer y from the cutter bar fixing plate u . Loosen the set screw i , and then remove the cutter bar fixin...
Page 48 - Shaft bush mechanism
LH4-B800E 2 - 23 2. DISASSEMBLY Remove the screw q , and then remove tube support U w . Remove the wicks e and r , and then disconnect the oil tube t . Remove the felt y , and then remove the wick u from bush F i . 2-14. Lubrication mechanism Shaft bush mechanism t r r e e w q i u y w
Page 49 - Needle zigzag mechanism
LH4-B800E 2 - 24 2. DISASSEMBLY Needle zigzag mechanism Remove the screw q , and then remove the felt support w from the motor bracket e . Remove the screw r , and then remove the tube support t . t t r r e w q q w
Page 50 - Oil tubes
LH4-B800E 2 - 25 2. DISASSEMBLY Oil tubes Remove the fastening band q . Remove the screw w , and then remove tube support M e . Disconnect the oil tube r that is connected to the oil terminal and the plunger pump. Remove the screw t , and then remove the tube support y . Remove the cord holder i , s...
Page 51 - Oil terminal mechanism
LH4-B800E 2 - 26 2. DISASSEMBLY Remove the screw q , and then remove the cap w and the felt @5 . Remove the screw o , and then remove felt base A r from the wick base support i . Remove the screw e , and then remove the wick base support i . Remove the two screws !4 , and then remove the oil termina...
Page 52 - Plunger pump mechanism
LH4-B800E 2 - 27 2. DISASSEMBLY Remove the three screws q , and then remove the oil filter bracket w from the bed. Remove the oil tube e that is connected between the plunger and the filter from the oil filter bracket w . Remove the two springs r and the two screws t , and then remove the pump filte...
Page 53 - Rotary hook lubricating mechanism
LH4-B800E 2 - 28 2. DISASSEMBLY Remove the spring q and the screw w , and then remove the rubber presser e from the bed. Remove the wick r from the felt support t . Remove the wick y from the felt support t . Remove the two screws u , and then remove the felt support t from the bed. Remove the end o...
Page 56 - -1. Lower shaft and idle pulley mechanism
LH4-B800E 3 - 1 3. ASSEMBLY 3. ASSEMBLY After attaching the timing belt to the idle pulley assembly q , insert the collar w . Insert the shaft e , and then install the assembly to the bed with the two set screws r . Install the timing pulley assembly t to the lower shaft y with the set screw u , and...
Page 72 - -9. Upper shaft and tension pulley mechanism
LH4-B800E 3 - 17 3. ASSEMBLY Install the two retaining rings q to the upper shaft w . Press-fit the ball bearing e as far as the retaining rings q . (Upper shaft assembly r ) Place the timing pulley U assembly t , timing belt y , bobbin winder pulley u and set screw collar assembly i onto the upper ...
Page 78 - -13. Thread breakage detection mechanism
LH4-B800E 3 - 23 3. ASSEMBLY Provisionally install the thread guide w to the thread breakage perceiving shaft q with the plain washer e , plain washer r and screw t , and then insert the thread breakage perceiving shaft q into the arm. Provisionally install the thread breakage sensor assembly y with...
Page 85 - Rotary hook lubrication mechanism
LH4-B800E 3 - 30 3. ASSEMBLY Pass the wick q through the collar w as shown in the illustration. Place the collar w onto the bush e as far as the base of the hollow. Insert the spring r into the bush e , and then insert the wick q as shown in the illustration. Push the end of the felt t into the hole...
Page 88 - Notes on making adjustments
LH4-B800E 4 - 1 4. Adjustment q w r e (a) (b) t y r (c) 4. ADJUSTMENT [When turning on the power to make adjustments]1. Turn on the power and set the sewing machine to the home position. Then press the RESET key to lower the presser foot before carrying out adjustments.“Adj” will appear in the numer...
Page 89 - -1. Adjusting the needle zigzag home position sensor position
LH4-B800E 4 - 2 4. Adjustment q 18.52 mm w t r e u y 4-1. Adjusting the needle zigzag home position sensor position Reference value Needle bar Presser bar Needle movesto the right N e e d l e m o v e sto the left 1. Turn on the power and set the sewing machine to the home position. Then press the RE...
Page 90 - -2. Adjusting the feed home position sensor position
LH4-B800E 4 - 3 4. Adjustment (1.5) r e w q q w 2 mm 4-2. Adjusting the feed home position sensor position 1. Turn on the power and set the sewing machine to the home position. Then press the RESET key to lower the presser foot. 2. If the clearance between the feed arm support q and the linear bushi...
Page 92 - -3. Adjusting the presser foot home position sensor position
LH4-B800E 4 - 5 4. Adjustment r e w q (A) q t y 4-3. Adjusting the presser foot home position sensor position Approx. 1 mm 1. Turn on the power. * Do not set the sewing machine to the home position. 2. Move the trimmer driving arm w in the direction of the arrow to move the upper thread trimmer driv...
Page 93 - NG; -5. Adjusting the needle and rotary hook timing
LH4-B800E 4 - 6 4. Adjustment t r e w q t r e w q i u y 0.01 - 0.08 mm o 0.3 mm O.K. NG 4-4. Adjusting the needle bar height Needle bar Cutter Turn on the power and set the sewing machine to the home position. Then press the RESET key to lower the presserfoot.1. Move the needle bar q to its lowest p...
Page 97 - -11. Adjusting the knife installation position
LH4-B800E 4 - 10 4. Adjustment X Y t r e w q i u y 0.3 mm w Push 4-11. Adjusting the knife installation position (Fig. A) (Fig. B) Pulled forward Knife groove Cutter Touching Adjust so that the upper thread trimmer knife and the cutter do not touch when the cutter is pushed down by hand.If the upper...
Page 98 - -12. Adjusting the cutter installation height
LH4-B800E 4 - 11 4. Adjustment q e q w 1.5 - 2 mm w The special needle plate has a narrow cutter groove of 0.3—0.4 mm, so use the accessory positioning plate q to adjust the cutter installation position.Furthermore, install the cutter holder w to minimize any play in the cutter during cutting. * If ...
Page 99 - -13. Adjusting the upper thread trimming
LH4-B800E 4 - 12 4. Adjustment Upper thread trimming adjustment procedure Adjusting the presser foot home position sensor position 4-3 (1) (1) Adjusting the longitudinal feed armassembly position 4-13-1 (2) (2) (1) Adjusting the trimmer driving armassembly position 4-13-2 (3) (3) (2) (1) Adjusting t...
Page 100 - -13-1. Adjusting the longitudinal feed arm assembly position
LH4-B800E 4 - 13 4. Adjustment r e q w t r e w 1 mm r e q w r e q w r w 1 mm 4-13-1. Adjusting the longitudinal feed arm assembly position 4-13-2. Adjusting the trimmer driving arm assembly position The following should be checked before adjusting the upper thread trimming. Aligned 1. Turn on the po...
Page 102 - -13-5. Adjusting the cutting depth of the upper thread scissors
LH4-B800E 4 - 15 4. Adjustment u y t q e w r e q 4-13-5. Adjusting the cutting depth of the upper thread scissors Clearance 0--0.5 mm Cam 1. Turn off the power (with the feed mechanism at the home position), and then slowly move the trimmer driving arm q forward until the driving arm roller e is at ...
Page 104 - -13-7. Adjusting the upper thread scissors gradual opening timing
LH4-B800E 4 - 17 4. Adjustment 0.5 mm 0.5 mm 0.5 mm 0.5 mm r r e w q q w (A) (B) (B) (a) 0.5 mm (a) (b) (b) (A) (C) 4-13-7. Adjusting the upper thread scissors gradual opening timing Starts touching at 1.5—2.5 mm Turn on the power and set the sewing machine to the home position. Then press the RESET...
Page 106 - -14. Adjusting the lower thread trimming
LH4-B800E 4 - 19 4. Adjustment (A) (B) r e w q 1 mm e y t y (A) (B) e q w (A) (B) e w 1 - 2 mm 4-14. Adjusting the lower thread trimming 4-14-1. Adjusting the lower thread trimmer fixed knife engagement amount Lower thread trimming complete 1. With the power turned off, move the lower thread trimmer...
Page 111 - -16. Adjusting the thread breakage detector
LH4-B800E 4 - 24 4. Adjustment 2 mm r e q w (A) y t e r (B) 1 mm 1 mm 0.1 - 0.5 mm e w e !0 o i u 4-16. Adjusting the thread breakage detector Touching Section (A) Section (B) 1. Tighten the lever stopper q inside the slotted hole. Loosen the screw w , and then adjust so that the distance (A) at the...
Page 113 - -19. Adjusting the upper thread feeding amount
LH4-B800E 4 - 26 4. Adjustment w q r e w q w w w F = 98 N (10 kgf) t 4-19. Adjusting the upper thread feeding amount 1. Loosen the screw q , and then turn the tension take-up lever w to adjust the upper thread feeding amount. * Move the trimmer driving arm by hand and check that upper thread feeding...
Page 115 - -23. Adjusting the needle up stop position
LH4-B800E 4 - 28 4. Adjustment t r e w q y w q 10 - 14 mm 4-23. Adjusting the needle up stop position 1. The needle up stop position is adjusted so that the index mark w on the machine pulley q is inside the mark r on the belt cover e . If adjustment is necessary, loosen the screw t of the machine p...
Page 116 - TROUBLESHOOTING GUIDE
LH4-B800E 5 - 1 5. Troubleshooting guide Cause Check Solution page Needle Needle facing Reattach needle properly As viewed from the direction of theface plate, attach needle so that the notched part of needle faces frontward - (Instruction) Needle installationheight Install the needle at the correct...
Page 120 - Beginning of sewing (2) Lower thread lifted up; Beginning of sewing (4) Uneven sewing pitch
LH4-B800E 5 - 5 5. Troubleshooting guide Cause Check Solution page Lower threadretainer Lower thread retaining amount Adjust the lower thread retaining amount. 4-19 Lower thread clamp Lower thread clamp timing Adjust so that the lowerthread clamp plateopens when the feed mechanism moves 6 --7 mm. Ad...
Page 125 - -9. Unraveling of thread trimmed by upper thread trimmer assembly
LH4-B800E 5 - 10 5. Troubleshooting guide 5-9. Unraveling of thread trimmed by upper thread trimmer assembly 5-10. Needle thread mis-trimming Check burr on upperside here Check burr here Cause Check Solution page Upper thread trimmer assembly Upper thread trimmer assembly position Refer to "5-8....
Page 126 - -11. Needle strikes upper thread trimmer
LH4-B800E 5 - 11 5. Troubleshooting guide Cause Check Solution page Upper thread trimmer assembly Upper thread trimmer assembly position Refer to "5-8. Needle thread runout" Upper thread scissors operating force Adjust so that scissors M open when theprojection is pressed with a force of 4 N...
Page 132 - -17. Feed mechanism does not operate or motor is out of step
LH4-B800E 5 - 17 5. Troubleshooting guide Cause Check Solution page Feed pulsemotor Cord connection Check the cordconnections andcontacts. - Upper thread scissors Upper thread scissors position Remove and re-install the upper threadscissors. Projection on scissors M is inserted. * Always make sure t...
Page 133 - -18. Needle does not zigzag or noise occurs when needle zigzags
LH4-B800E 5 - 18 5. Troubleshooting guide 5-18. Needle does not zigzag or noise occurs when needle zigzags 5-19. Sewing machine stops during sewing Cause Check Solution page Zigzag home position sensor Zigzag home positionsensor position Adjust the zigzag home position sensorposition. 4-2 Stopper St...
Page 134 - ELECTRIC MECHANISM; -1. Precautions at the time of adjustment
LH4-B800E 6 - 1 6. ELECTRIC MECHANISM 6. ELECTRIC MECHANISM 6-1. Precautions at the time of adjustment Pay attention to the following when opening the control box for maintenance. ■ Electric shock Some large capacitors may have a high voltage remaining in them for up to 5 minutes after the power is ...
Page 135 - -2. Components inside the control box and the operation panel
LH4-B800E 6 - 2 6. ELECTRIC MECHANISM 6-2. Components inside the control box and the operation panel The following are brief explanations of components inside the control box. For details on connections, refer to "6-9. Control circuit block diagram". - Main circuit board This circuit board i...
Page 156 - DIPSWB
LH4-B800E 6 - 23 6. ELECTRIC MECHANISM Setting item Work clamp size: 7.3 × 75 mm (6.0 × 70 mm) Work clamp size: 7.3 × 36 mm (6.0 × 32 mm) Work clamp size: 7.3 × 24.5 mm (6.0 × 20 mm) Work clamp size: 6.8 × 36 mm (5.4 × 32 mm) Work clamp size: 6.8 × 24.5 mm (5.4 × 20 mm) Panel DIP switches B-7 and B-...
Page 159 - -6. Description of machine motor parameters
LH4-B800E 6 - 26 6. ELECTRIC MECHANISM 6-6. Description of machine motor parameters * To change the machine motor parameters, press and hold the ENTER key and then turn on the power. Machine motor parameter setting mode will then start. * Do not change the default values for the machine motor parame...
Page 167 - Leg; Machine head
LH4-B800E 6 - 34 6. ELECTRIC MECHANISM 6-9. Control circuit block diagram POWER P6 B10P-VH 10 MP0V 9 MP0V P0V M55V 8 M55V 7 SOV 6 5 E24V 4 P0V 3 +55V 2 +55V 1 PER P3 VALV P4 Green/Yellow Leg Green/Yellow White Red OUT220V IN240,380,400,415V Emergency stop Blue Black Brown WhiteBlack Red home positio...
Page 168 - SERVICE MANUAL
SERVICE MANUAL Printed in Japan 118-H80 I1050811H 2001.07. H (1) BROTHER INDUSTRIES, LTD. 15-1, Naeshiro-cho, Mizuho-ku, Nagoya 467-8561, Japan. Phone: 81-52-824-2177
