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4.7 Setting the retaining spring of the hook thread

The retaining spring (1) holds the hook thread after having

performed the trimming. It is to be set in such a way that the

force necessary for pulling out the thread from the retaining

spring (1) is approximately equal to the force necessary for

pulling out the thread from the hook.

Caution! Danger of injury!

Switch off the main switch! Before starting the setting

operation, wait until the motor stops!

- Using the screw (3),set the height of the top edge of the

retaining spring (1) 1 mm below the top edge of the moving

trimming knife.

- Shape the retaining spring (1) in such a way that it fits close

with all  its surface (without wedge) onto the moving  trim-

ming knife (4).

- Shape the retaining spring in such a way that it fits close, with

the slightly tightened screw (2), onto the moving trimming

knife without any pressure.

- Tighten the screw (2), until the necessary force for pulling the

thread from the retaining spring is attained. The pulling force is

tested using a screwdriver according to the illustration.

Caution!

The setting of the retaining spring (1) depends on

the setting of the hook tension and differs then

according to the respective sewing category.

The adjusting  screw  (2)  should  not be screwed in in such a

way that the retaining spring gets over the perimeter of the

moving trimming knife.

4.8 Setting the switching of electromagnets

The electromagnets of the trimming device and loosening of the

tensioner must work in accordance with the diagram. This is

ensured by setting the stopmotor (see the instructions for

use of the stopmotor).

1- 1. position of the needle (225

°

 on the handwheel)

/135

 Mini-stop QE 3760/DA47MS/

2- 2. position of the needle (64

°

 on the handwheel)

3- position of stopping the tensioner  (10

°

 ÷ 25

°

 on the hand-

wheel)

4- movement of the pickup roller

5- current of the trimming device electromagnet

6- current of the tensioner loosening electromagnet

5

.

Lifting the top roller by electromagnet

5.1 Description

The core of the electromagnet, respectively its pin must be set in

such a way that the presser foot lifting is enabled.

5.2 Setting the electromagnet pin

Caution! Danger of injury!

Switch off the main switch! Before starting the

setting operation, wait until the motor stops!

- Unscrew the cap of the core (1) of the electromagnet.

- Shift the core (2) with the bar (3) and loosen the locking

screw (4).

- By screwing the pin (3) in the core (4), set their mutual

position in such a way that the core is fully pushed in with

the maximum presser foot lift.

- Tighten the locking screw (4).

- Screw on the cap (1).

4

5

6

1

3

2

2

4

1

3

4

1

4

1

2

0,8 mm

4

1

2

3

1

4

Summary of Contents for 4280-6

Page 1: ... for service 4280 6 Minerva Boskovice a s Sokolská 60 CZ 680 17 Boskovice Tel 420 501 453434 453433 494111 Fax 420 501 452165 http www minerva boskovice com Edition 06 2001 Printed in Czech Republic 735 342 000 450 ...

Page 2: ...with needles side by side 3 5 Threadtensionersandlimiter 10 3 5 1 Description 3 5 2 Setting the tension of the main and auxiliary tensioners 3 5 3 Setting the tensioning mechanism of the main tensioners 3 5 4 Setting the adapting spring 3 5 5 Setting the thread limiter 3 6 Feeding mechanism of the needle feed and of the lower feed wheel 12 3 6 1 Description 3 6 2 Stitch length mechanism 3 6 2 1 Se...

Page 3: ... oil 3 14 3 Multiple oil use 4 Thread trimming 26 4 1 Description of the trimming mechanism 4 2 Setting the pickup roller 4 3 Setting the cam 4 4 Setting the fork 4 5 Setting the moving knife 4 6 Setting the fixed knife 4 7 Setting the retaining spring of the hook thread 4 8 Setting the switching of the electromagnets 5 Lifting the top roller by electromagnet 28 5 1 Description 5 2 Setting the ele...

Page 4: ... actions of the operator may lead to dangerous situations In industrial sewing machines Minerva attention should be paid to the following still remaining possible sources of injury 1 Moving sewing needle risk of injury when sewing with raised pressure foot or top roller because the finger guard is then positioned too high 2 Moving thread take up lever risk of injury when inadvertently or intention...

Page 5: ...rning the screws 3 and 4 set the required distance A After having set it tighten carefully the screws By axial shifting of the gear wheel 5 set the axial clearance in such a way that this clearance is the least possible but sufficient for turning easily the hook Tighten carefully the screws 2 Caution One of these screws must bear on the flat of the shaft 6 3 1 3 Setting the distance of the hook fr...

Page 6: ... required clearance between the needle 2 and the protecting sheet 1 When turning to the right the protecting sheet shifts out from the groowe and inversely Check up the protecting effect in pushing against the needle in the sense of the arrow 5 The hook point must not catch the needle If so set up the protecting effect correct eventually the setting of the distance of the hook point from the needl...

Page 7: ...e moment when the hook point comes to lie opposite the needle 4 The wheel 2 is to be set with its gear rim symmetrically to the centre of the gear wheel 1 The clearance between the gear wheels is to be the least possible Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Set the angle of 2O5 on the handwheel 6 and lock it with the s...

Page 8: ...ed for a big or a small hook The needle bar holder 4 is mounted through the pin 5 in a rotating way in the arm 6 In its top part the holder is guided by the guide pin 7 The movement for the needle feed is given to it by the connecting rod 8 driven by the feeding shaft 9 The connecting rod 8 is mounted by eccentric pin 13 with needle bar hoder 4 The connecting rod 10 of the needle bar 11 on the loo...

Page 9: ...ain shaft Set the connecting rod pin as follows Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Remove the front guard Loosen the screw 1 of the connecting rod 3 pin 2 Set the pin into the corresponding position and tighten anew the screw The correct position is given by the flat on the pin 2 on which the screw 1 is tightened 3 2...

Page 10: ...ait until the motor stops Loosen the screws 4 from the rear side of the post too Shift the post 1 in the right direction in such a way that the distances B are equal with both needles Tighten up the screws 4 and check up the correctness of setting Loosen the screw 3 of the needle bar carrier Shift the needle bed 2 in such a way so that the required stitch width of needles A is attained Tighten up ...

Page 11: ...et the guide 1 in the direction of sewing in front of the left needle at the moment when the needle starts piercing the material and set at the same time the side clearance between the guide and the right hand needle tighten then the screw Check up the influence of the setting on the stitch locking 3 4 3 Setting the rear guide For different stitch widths of needles there is always used for all sew...

Page 12: ...of sewing the guide is to be set in such a way that the contact of the guide with the material is at the same spot as the contact of the feeding wheel with the material Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Loosen the screws 7 and set the guide 3 into the axis of the stitch width of the needles and set the guide in its ...

Page 13: ... by the dynamometer 2 as it is shown on the illustration The size of this force differs according to the category of sewing and is indicated in the par 11 2 The tension of the auxiliary tensioner is regulated using the nut 3 It should be the least possible but sufficient for unthreading the thread from the sewn material when removing the sewn material from the pressing element without leaving the ...

Page 14: ...e distance C 3 mm set the angle A 45 and tighten the screw 11 Turn the washers with their noses 7 in such a way that the distance B 3 mm is attained Put the screwdriver into the slit in the bushing 8 and turn it in counterclockwise direction until the spring 9 touches slightly the nose of the washer 7 Turn then still the bushing 8 by 1 4 revolution Tighten the nut 1 In this way the whole mechanism...

Page 15: ...andwheel 2 and lock it with the screw 5 which is included in the accessory of the machine tighten it carefully Insert the setting stick 3 into the hole in the eccentric 1 and prop it against the feeding shaft 4 Shift axially the eccentric on the shaft up to its extreme position to the right or to the left and place it in the medium position Tighten the screws of the eccentric 6 to the utmost one s...

Page 16: ...he stop the maximum stitch length valid for the given sewing category and the stitch width is attained The scale on the control knob is to be oriented in such a position that the respective maxi mum stitch length on the scale is against the marking on the machine arm Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Screw in the sc...

Page 17: ... at the same time the friction connection with the cover of the clutch 1 is disconnected Within a short instant when engaging and disengaging with the carrier plate 5 there are in a friction engagement both the cover 1 and also the star 4 namely in the dead centre of the connecting rods 2 and 3 The setting of the change over of clutches is done by tightening or by loosening the nut 13 3 6 4 1 2 Se...

Page 18: ...he shifting of the clutches is done at the moment when the clutch disks 3 do not move which means when they are at the dead center of their oscillating movement This corresponds to the angle 90 on the handwheel Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Loosen the screws of the indented pulley of feeding and shift it to the ...

Page 19: ...ttained but only to the measure of not deteriorating the beginning of sewing after the carried out thread trimming With every correction of the teeth height the tension of the chain 2 is to be corrected Caution Dangere of injury Switch off the main switch Before starting the setting operation wait until the motor stops Loosen the screw 3 Loosen the screw 4 Loosen or tighten the screw 5 and push si...

Page 20: ... 2 mm Tighten the screw 4 Setting the force of the top roller 1 In screwing in the screw 2 the force of the top roller is increased and inversely 3 7 Feeding mechanism of the top roller 3 7 1 Description The starting movement for the drive of the top roller feeder is the bottom feeding shaft From this shaft the movement is transmitted by the indented belt 1 onto the top feeding shaft 2 A component...

Page 21: ...setting thereof is to be done as follows Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Loosen the screws 1 of the pulley 2 Set the pulley 2 in such a way that the distance of 5 mm is attained in accordance with the illustration Tighten the screws 1 3 7 4 Setting the tensioning roller The tensioning roller of the indented belt o...

Page 22: ...ay that it is possible to remove the indented belt 23 from the arm of the machine Replace the belt with a new one and proceed to the assembly inverted procedure of dismantling Proceed to the setting operation according to the par 3 7 2 3 7 3 and 3 7 4 3 7 6 Setting the feeding difference The size of feeding by the driven top roller is regulated by means of a regulating screw The top roller feeding...

Page 23: ... diameter of 25 mm and with the diameter of 35 mm The suitability of the diameter used depends on the type of sewing and on the concrete technological operation There are in general valid the following principles for the selection of the wheel diameter ø 25 mm for sewing small radii ø 35 mm for sewing straight sections or big radii for sewing with great passages to thicker materials 3 7 8 2 Forwar...

Page 24: ...ement of the top roller When replacing the top roller proceed as follows Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Unscrew the screw 1 Unscrew the screw 3 with the washer 2 Remove the driven top roller with the holder 4 from the holder 5 and from the articulated shaft 8 Mount another top roller in inverted procedure to dism...

Page 25: ...bbin the pressing function of the cam on the winders shaft is interrupted and it moves in the sense of the arrow A fine setting is to be done on an incorporated condition in the machine Using the screw 2 the position of the friction part of the pickup lever 1 is adapted In opening the lever the stopping function is accelerated Its inverse function delays it A test is to be done after having insert...

Page 26: ...en the hook is blocked but the clutch does not disengage the disengaging moment of the clutch is to be reduced in turning the screws to the left Caution The clutch guarantees only one mutual position of the hub of the lower shaft 2 and that of the belt wheel 1 No checking according to the gauge marks is needed Putting the clutch out of operation by excessive tightening of the screws 3 can cause wh...

Page 27: ...ch off the main switch Before starting the setting operation wait until the motor stops The belt is correctly tensioned when the opposite sides of the belt approach one to another by up to 20 mm in applying the force of 10 N The belt is tensioned in turning respectively the motor in its holder 3 12 2 Replacing the V Belt Caution Danger of injury Switch off the main switch before starting the setti...

Page 28: ...es 3 14 2 Refilling oil For lubricating the machine oil Esso SP NK 10 is used or other oil with the same quality When putting the machine into operation each mechanism of the machine is to be lubricated with several drops of oil Oil is only refilled thereafter into the oil reservoirs using an oil can into the holes in the oil level indicators The oil reservoir 1 is to be filled up to the half of i...

Page 29: ...against the bracket 5 and at the same time the shaft 2 up to the stop against the shaft 3 With the holder 1 held on the stop shift the shaft 2 in such a way that there appears the gap A 0 2 to 0 4 mm and tighten the screw 4 Check the gap A in shifting the armature 6 4 3 Setting the cam The position of the cam 1 against the shaft 2 is to be such so that when the adjusting pin is in contact with the...

Page 30: ...itch off the main switch Before starting the setting operation wait until the motor stops Loosen the screws 4 and 5 Turn the moving trimming knife 1 in the sense of the arrow and set it in height Tighten the screw 5 Turn the moving trimming knife 1 into its starting position in such a way that the measure A 0 1 to 0 5 mm is attained Tighten the screw 4 4 6 Setting the fixed knife The fixed trimmin...

Page 31: ...egory The adjusting screw 2 should not be screwed in in such a way that the retaining spring gets over the perimeter of the moving trimming knife 4 8 Setting the switching of electromagnets The electromagnets of the trimming device and loosening of the tensioner must work in accordance with the diagram This is ensured by setting the stopmotor see the instructions for use of the stopmotor 1 1 posit...

Page 32: ... way that it enables the maximum stitch length when sewing in forward and in rearward sense If this position is not correct the length of the stitch will be shortened in one or the other feed direction 6 2 Electromagnet height setting Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Set the maximum stitch length Set the position o...

Page 33: ...el position sensor The detailed information concerning the drive the control panel and the setting of the position sensor is given in the manual of the drive and of the control panel 9 Lighting 9 1 Mounting on the machine head Caution Danger of injury Switch off the main switch Before starting the setting operation wait until the motor stops Mount the lamp on the machine head using the screws 3 Th...

Page 34: ...m sewing 3 medium heavy duty sewing 4 heavy duty sewing In the factory where this machine has been manufactured it has been set up with respect to the standard parameters of the required stitch width and the required sewing category which is designed by the number included in the commercial designation of the machine If the user desires changing the given setting to another sewing category or stit...

Page 35: ...o correct the setting of the distance of the shuttle from the needle according to the paragraph 3 1 3 and at the same time the setting of the fixed trimming knife of the trimming device according to the par 4 6 8 There are in use various types of feeders with the purpose of avoiding imprinting the teeth in the lining leather Otherwise it is possible to use any feeder 11 3 Table of possible stitch ...

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