How to loosen the sewing machine foot. An exhibition of the presser foot, for all classes of machines. Sewing with a sewing machine

Let's try now to figure out for what purposes it is required adjust the pressure of the presser foot onto the fabric.

A regulator for the pressure of the foot on the fabric was standard on vintage sewing machines. In modern sewing machines, it is less common and is not given much importance. So which sewing machine to buy, with a presser foot pressure regulator or not? What do we lose if we choose a clipper without a pressure regulator?

The pressure regulator allows us to adjust the degree of influence of the foot on the fabric, which the foot presses against the feed dog feed dog. Thus, the size of the stitches produced can depend on the pressure of the foot.

The foot can be made of various materials - chrome steel, plastic, Teflon. Accordingly, different feet will slide on different materials with different amounts of friction force. Another factor is tissue distortion when the tissue is pressed against the feed teeth. Select the optimum presser foot pressure so that the fabric is effectively fed under the needle by the feed dog and so that the fabric does not deform when pressed against the feed dog. Even the most modern computer sewing machines with automatic adjustment of the presser foot pressure cannot correctly calculate the friction of the presser foot and the resulting stretch or distortion of the fabric.

The best solution is experiment and testing. If you have a presser foot pressure regulator, you can adjust the setting so that the preset foot glides optimally on the selected fabric. So choose a clipper with a foot pressure regulator - it will only get better, it will not be worse in any case.

Let's give simple example... If you use a GPS navigator, then you follow its instructions, fully rely on it. You drive from point A to point B and do not think about anything, you do not remember landmarks. As soon as your navigator breaks down, then you first start to panic. Then you turn on all your senses and observation, and you will explore the unknown area so much that you will never get lost here, even without a navigator. The same can be said about sewing. Adjust, experiment, try - and you will always achieve what you need.

Suppose you are sewing 2 pieces of stretch knit together, and towards the end of the seam you find that one piece is stretched out relative to the other - it is longer. The reason for this may be the incorrectly selected pressure of the presser foot on the upper layer of the fabric - the upper and lower layers are fed under the needle at different speeds, the layers are shifted.

How to adjust the presser foot pressure? Adjust the pressure of the foot and see the result. If the seam looks bad, start increasing the pressure a little. If the result becomes even worse, then do the opposite - decrease the pressure of the foot.

Sewing machines can seem dauntingly difficult to those who don't know how to use them. Be that as it may, do not let the fear of unknown operations and skills required to use a sewing machine stop you from creating textile wonders! Use this step-by-step guide to set up and operate your sewing machine so you can start making your own clothes.

Steps

Sewing machine parts

Find the power button. It may sound silly, but locating the power button is the most important step! It can be found in different places depending on the model of your sewing machine, but most often you will find it on the right side of the sewing machine.

Find a reel seat. This is a small plastic or metal stick that sticks out from the top of the sewing machine and is designed to hold a spool of thread.

Find the thread guide. The thread guide guides the thread from the spool attached to the top of the machine to the bobbin winder. It is a geometric metal section that sticks out on the upper left side of the sewing machine.

Find a winder. To the right of the reel seat is another, even smaller, metal or plastic pin, next to which there is a small horizontal wheel. This is a bobbin winder and its stop. They work together (together with the bobbin and thread) to wind the thread around the bobbin before starting sewing.

Take a look at the buttons to adjust the stitches. They may be in different places depending on the model of your sewing machine, but they usually look like buttons with small pictures and are located on the front of the sewing machine. These buttons allow you to change the type of stitches you can use, the length of the stitches, and their direction (forward and backward). Check the instruction manual for your sewing machine for the purpose of each button.

Determine the location of the thread take-up. When you are ready to thread the sewing machine, start pulling the thread from the top of the spool, through the thread guide, and then into the thread take-up. This is the lever (with two grooves cut out) located on the front left side of the sewing machine. Usually you can see printed numbers and arrows next to it, explaining how to thread the sewing machine and in what order.

Find a tension adjuster. The tension dial is a small number wheel located next to the thread take-up. It controls the thread tension while sewing; if the tension is too high, the needle will bend to the right. If the tension is not sufficient, the thread will tangle on the back of the fabric you are sewing.

Locate the needle clamp screw. This is a metal tool that holds the needle while sewing. It is located under the sleeve of the sewing machine and is very similar in shape to a large nail. It attaches to the right side of the needle.

Find the foot. This is the metal part under the needle holder and looks like tiny skis. When you lower the foot, it holds the fabric in place and guides it as you sew.

Find the presser foot lever and practice raising and lowering the presser foot. It should be behind or to the right of the needle holder and needle. To test the lever, lower it down and lift it up.

Find the stitch plate. The stitch plate is the silver pad just below the needle. Very simple, right?

Find a transporter. The feed dog is a small metal guide that sits on the needle plate, under the foot, and guides the fabric as you sew. Pay attention to the two metal rows under the foot - this is the conveyor.

Find the spool stopper and release. The spool is a small spool of thread that sits on the bottom of the sewing machine and feeds the second thread to the needle, which is needed to create the stitches from the inside. There is a spool stop under the metal plate, and there you will also find a button or lever that releases it. You will need it to secure the spool before sewing.

Setting up the sewing machine

1. Place the sewing machine on a stable table, work area, desk, or sewing machine stand in front of you. Sit on a chair that is the appropriate height relative to the table you are using. The sewing machine should be positioned with the needle on the left and the rest on the right, relative to you. You will have to check a few parameters first and get a little familiar with the sewing machine, so don't plug it in at this stage.

   Insert the needle securely. The needle has a flat side, so there is only one way to insert it: the flat side must be facing back. On the other side, there is a groove at the bottom of the needle, usually opposite the flat side of the needle. This notch always faces in the direction of the thread passing (the thread passes through this notch when sewing the fabric up and down with the needle) Insert the needle as described and securely tighten the screw holding the needle.

   Install the coil. Sewing machines use two sources of thread - the upper thread and the bobbin thread. The bottom one is on the reel. To wind the thread onto the spool, place the spool on the upper spool seat, which is used to wind the thread. Follow the instructions and wind the thread from the thread spool through the thread take-up onto the bobbin. Turn on the thread take-up mechanism and wait for it to stop by itself, when the bobbin is fully wound.

   • When the bobbin is ready, place it in the designated spot, under the needle, on the bottom of the sewing machine. Leave the end of the thread outside to insert it into the needle.

2. Thread the sewing machine. The spool of thread on the top of the sewing machine should be unrolled and attached to the needle. To do this, take the end of the thread and pull it through the thread take-up from the top of the sewing machine, and then lower the thread down to the foot. The sewing machine should have small numbers and arrows to show you the order in which the thread runs.

   Take out both threads. Run the scissors under the foot to loosen the ends of both threads. You should have two ends - one from the thread coming through the needle and the other from the thread coming from the bottom spool.

   Plug the sewing machine into a power outlet and turn it on. Many sewing machines have built-in lighting to help you determine if it is working and if it has electricity. The power button is often located on the right or back of the sewing machine, if any. Some sewing machine models do not have such a button and will turn on as soon as they are plugged into an outlet.

   • Also connect the foot control to the sewing machine. Place the pedal in a comfortable position under your foot.

   SPECIALIST'S ADVICE

   

   Pattern constructor

   Daniela Gutierrez-Diaz is a professional pattern and clothing designer at DGpatterns. Creates modern and unique silhouettes suitable for everyday life. Her successful blog On the Cutting Floor contains sewing tips and a variety of patterns in PDF format.

   

   Pattern constructor

   Keep your sewing machine clean. Daniela Gutierrez-Diaz, a professional pattern and clothing designer, advises: “From time to time take your sewing machine to a specialized sewing machine service center, in order to be cleaned there... It is advisable to do this regularly, especially if you use the sewing machine constantly».

   Sewing with a sewing machine

   Choose a straight stitch, medium size. Check the instructions for how to do this on your model of sewing machine. On this model, the stitches are set by turning the lower knob on the right side of the machine until it clicks. Always set or change the stitch pattern while the needle is up by removing the fabric as it can move the needle.

• The straight stitch is the most popular stitch in sewing. The next most popular stitch is the zigzag stitch, which is used to finish the edges of fabrics and counteracts its unraveling and shedding.

Practice on bad material. Choose a plain fabric, not jersey, for your first sewing experience. Do not use fabric that is too thick for your first attempts at sewing machine. Denim or flannel is very difficult to work with due to their density.

Place the fabric under the needle. Stitch with the stitching aside to the left of the machine. Putting the fabric to the right can cause uneven stitches.

Lower the foot. Locate the lever on the back or side of the needle to raise and lower the presser foot.

• If you pull lightly on the fabric that is pressed down with the foot, you will realize that it is held quite tightly. When you stitch, the sewing machine uses a protractor to move the fabric at the correct speed. Therefore, there is no need to pull the fabric through the sewing machine by hand; in fact, pulling the fabric can cause the needle to bend or damage your design. You can adjust the speed and size of the stitches using the buttons on the machine.

1. Hold the loose ends of both threads. For the first few stitches, you will need to hold the ends of both threads to avoid tangling in the fabric. After you have sewn a little, you can let go of the ends of the threads and use both hands to control the fabric and the sewing machine.

   Step on the pedal. The pedal is responsible for controlling the sewing speed. It's like the gas pedal in a car - the harder you press, the faster the sewing machine will run. At first, depress the pedal very slowly and just enough to start the sewing machine.

   • Your sewing machine may have a knee-operated button instead of a pedal. In this case, use your knee to push it.
   • You can use the upper wheel on the right side of the sewing machine to force it to sew, or move the needle by hand.
   • The sewing machine will automatically guide the fabric away from you. You can guide the fabric under the needle in a straight line or at different angles. Practice stitching straight and wavy. The only difference is how you bring the fabric to the needle.
   • Do not insert or pull on the fabric under the needle. This may stretch the fabric or break the needle, or the seam may become jammed into the bobbin. If you feel that the sewing machine is not working fast enough, depress the pedal harder, adjust the stitch length, or (if necessary) buy a faster sewing machine.

2. Find a button or a reverse lever and try it out. It allows you to change the direction in which the sewing is going, so the fabric will move towards you, not away from you. Usually this button or lever is held by a spring, so you will have to hold it in order to continue sewing in the opposite direction.

   Use the handwheel to raise the needle to its extreme point. Then raise the foot. The fabric should now be easy to remove. If the thread pulls back when you try to remove the fabric, check the needle position.

   Cut the thread. Many sewing machines have a notch in the pin that holds the foot. You can cut the threads by holding them with both hands and tracing them over the barb. If there are no barbs or you want to cut the threads more carefully, then use scissors. Leave the ends of the threads in order to continue sewing the next seam.

3. Practice stitching. Pin together two pieces of fabric, right-side-to-side, right at the edge. The seam will be 1.3 cm to 1.5 cm from the edge. You can stitch the fabric in one layer (and you might want to do this to reinforce the edge), but since the purpose of most sewing machine work is to join two pieces of fabric, you need to get used to stitching multiple layers of fabric and using pins. ...

   • The fabric is fastened right-side to each other so that the seam stays on the wrong side. Right side is the side that will be outside when sewing is finished. On dyed fabric, the face side is usually the brighter side. Some fabrics may not have a front side.
   • Attach the pins perpendicular to the line along which the seam will run. You can stitch directly onto the pins and later easily remove them from the fabric, but doing so can damage the sewing machine, fabric, or pins. It is safest to remove the pins as soon as the needle approaches them, as if the needle accidentally hits the pin it will break and the needle will bend. Be that as it may, prevent the needle from hitting the pin heads.
   • When you follow the fabric, pay attention to where the material is moving. The seams can go in different directions, but most sewing projects are subsequently trimmed so that the seams run parallel to the edge. Also, pay attention to the direction of the pattern, if your fabric has one, and position the fabric so that the pattern runs from top to bottom on the right side. For example, floral or animal prints, or stripes or other designs should go in the right direction.

Malfunctions encountered when setting up machines are shown in photos 1 and 2.

And the way to eliminate them, in four stages.

In photo 1, the foot is up. Needle bar - goes down and catches the foot.

1. Pressure screw.
2. Spring.
3. Bracket with screw 5.
4. Shaft of the foot.

1. Foot.
2. Needle bar.
3. Needle plate.

Photo 1.

On photo 2, the foot is lowered.

The foot is high and does not reach the throat plate.

1. Pressure screw.
2. The case, a pressure screw is screwed into it.
3. Spring.
4. Bracket with screw 5.
5. Screw - for adjusting the foot bar in height.
6. Lever - for raising the presser bar.
7. Shaft of the foot.
8. Lower body. Sometimes it contains a lower bushing.

For this topic, it doesn't matter where the bushings are.

1. Foot.
2. Needle bar.
3. Bracket with screw, on the needle bar.
4. Needle plate.
5. Transport block.

An exhibition of the presser foot, for all classes of machines.

It often happens that when the presser foot is raised, the needle cannot go down - it rests on the presser foot. And when sewing, when jumping from thin to thick or vice versa, from thick to thin, it occurs under looping from below. This is what we will now eliminate:

1. We lower - the lifting handle, the rod of the foot holder, down! (Photo 1 and 2 No. 6)
2. Turning the handwheel, lower the needle to the lowest point zero.

The teeth of the conveyor block - should go down, below the top, the stitch plate - also to the bottom point zero. (photo 3 No. 6)

All! No more touching the flywheel, don't touch it! The foot should be on the surface of the throat plate! If it didn't. Or the presser foot just touched — with the front — the surface of the throat plate.

We can fix it like this:

First step:

The foot mechanism is an integral part of the fabric motor mechanism and is kinematically connected with the device for loosening the upper thread; The machine uses an articulated foot 1 (Fig. 19), attached to the rod 2 with a screw. The guide for the rod is bushing 3 pressed into the machine head. From above, a bracket 18 is freely put on the sleeve, on which a bevelled plate 5 is fixed with a screw, pressing on the rod of the upper thread tension regulator: when lifting the foot. The arm extension is located in the guide groove of the machine head body. A link 8 is connected to the bracket with a hinge screw, into the hole of which the lever pin 10 is inserted. The lever is held by two hinge screws 9 screwed into the machine sleeve body. The right arm of the lever 10 is connected to a rod 12, the position of which is fixed by a cotter pin 14, A spring 13 is put on the lower end of the rod 12 passed through a hole in the machine platform, abutting against the cotter pin 14.

A guide 7 is fixed on the rod 2 by a tightening screw 18, the branch of which is located in the groove of the machine head and prevents arbitrary rotation of the rod with the tab around their axis.

The pressure of the foot on the fabric is produced by a leaf spring 16, which is put on the right end of the hinge screw 15. The left end of the leaf spring abuts against the ball 17 inserted into the end hole of the rod 2 of the foot. The thrust screw 11 creates the pressure of the leaf spring 16 and

feet 1 on the fabric.

To raise the foot manually, a pin with a lever 4 is inserted into the hole of the machine head, a spring-loaded cam 20 is put on the pin, which can be rotated together with the pin and the lever for lifting the foot manually. When the lever 4 is turned clockwise, the cam 20 presses on the branch of the bracket 6. The bracket, moving upward along the stationary sleeve, presses on the guide 7, which rises together with the rod 2 and the tab 1. At the same time, plate 5, with its bevel acting on the tension regulator rod, releases the upper thread located between the convex tension washers.

Figure 19. The mechanism of the machine presser foot 97-A class.

The machine is equipped with a presser foot lifting knee lifter located under the industrial table cover. If it is necessary to raise the presser foot, the worker moves the knee press to the right. The lever arm raises the rod 12. The rod turns the lever 10 counterclockwise, and the link 8 raises the rod with the foot.

The height of the presser foot above the stitch plate is adjusted by moving the pin 2 with the presser foot after loosening the screw 18. At the same time, make sure that the presser feet do not touch the needle. The position of the foot horns relative to the needle is adjusted by turning the rod with the foot around its axis. The force of pressure of the presser foot on the fabric is regulated by the screw 11. The height of the presser foot is changed at the lower position of the needle, and, consequently, the lower position of the rail.

Figure 20. Lubrication of the mechanisms of the machine 97-A class.

As mentioned earlier, in the car 97-A class. lubrication of the main mechanisms is carried out forcibly. For this, a double vane pump H is installed under the platform of the machine (Fig. 20.b), one part of which is intended for sucking oil from the oil pan and pumping it to the rubbing surfaces of the machine parts, and the other for sucking out the accumulated oil from the front of the machine head and returning it back to the sump located under the machine platform.

A double vane pump (Fig. 20, a) consists of a housing 1, two rings 2, a washer 6, a shaft 3 and a cover 8. The parts are connected to each other by two pins 10 and three screws 9. In the grooves A of shaft 3, sliders 4 are inserted, between which are located springs 5, constantly pressing the gates 4 to the inner side of each ring. The center of the hole of the rings 2 is offset relative to the center of the shaft 5, therefore the outer surface of the shaft 3 touches on one side the edge of the inner surface of the rings. Washer 6 separates the suction chamber 11 from the discharge chamber 12.

At the upper end of the shaft 3, a gearwheel 23 is fixed (see Fig. 20, b), which is in engagement with a worm 22 fixed on the camshaft with a gear ratio i \u003d 7: 1.

When the camshaft rotates, the worm pair transfers rotation to the pump shaft 3. Oil from the sump through a PVC tube 8a enters the pumping cavity 12 (Fig. 20, a) of the pump, and from the pumping cavity into the distribution nozzle 13 and the pipes 20, 24, 25 connected to it (see Fig. 20, b). Through the tube 20, the lubricant enters the reservoir 19, from where it flows to the channel to the surface of the main shaft and through the spiral groove of the shaft through the transverse hole into the shaft cavity.

The wick, located in the cavity of the main shaft, absorbs oil, which, through the holes and under the action of centrifugal force, enters the ball bearing of the main shaft and the needle bearing of the needle bar connecting rod.

Through pipe 17, the oil enters the needle bar bushing, and through pipe 21, to the rear ball bearing of the main shaft. The oil accumulated in the front part of the machine head is sucked in by the pump chamber 11 through the pipe 18 (Fig. 20, a) and drained into the sump forcibly.

The surface of the double eccentric of the cloth engine mechanism, as well as the inner surface of the front and middle camshaft bushings, are lubricated with oil coming from the pump through the tube 24 and the inner bore of the camshaft. The remainder of the oil in the inner camshaft is fed to the gears of the shuttle mechanism. Through pipes 15 and 26, the oil flows to the cracker of the rack lifting shaft and to the hinge joints of the frame 14 of the shaft 16 of the fabric motor unit.

Figure 21. Scheme of threading the needle thread of the machine 97-A class.

The shuttle mechanism is also forced lubricated. Through pipe 25 (see Fig. 20, b), oil from the pump is supplied to the spiral groove A of the shuttle shaft 33 (Fig. 16) and, moving to the left along the groove, lubricates the inner surface of the right sleeve. In this case, one part of the oil enters the hole B, penetrating into the shuttle shaft 33, the other part enters the space between the sleeves 32 and 34, providing lubrication of the inner surface of the left sleeve 32.

The oil inside the axial channel of the shuttle shaft 33 spreads in two directions. Moving to the left, the oil along the wick F through the hole in the screw 31, through the channel 35a of the shuttle 25, falls on the rim of the spool holder 24. Moving along the axial channel to the right, through the hole B, the oil enters the annular channel of the right bushing and flows down the channel D into the sump-cutter.

The wick inserted into the axial bore of the shuttle shaft must be replaced with a new one each time it becomes clogged with dirt.

The amount of oil supplied to the shuttle 25 is adjusted by the screw 30. If the screw 30 is screwed in, then the section of the channel E will be reduced, and the amount of oil supplied to the shuttle will increase.

When adjusting the oil supply to the hook, it is necessary to screw in the screw 30 to the end, and then unscrew it by 2.5 turns. Checking the oil supply to the shuttle set is carried out as in the 1022 cl. In fig. 21 shows the threading diagram of the needle.

Machine 852 (× 5) cl. PMZ.

Industrial sewing machine 852 (× 5) cl. PMZ is designed for sewing with two parallel shuttle-weaving stitches of linen, suit, raincoat materials made of natural and mixed fibers (Fig. 22). Features of the machine are that the needles, in addition to vertical movements, deviate along the lines; Central bobbin shuttles are used, rotating in a horizontal plane and equipped with diverters. Threading the upper and lower threads. Bobbins or spools of thread are placed on bobbin stands. The threads are passed through the holes of the tubular thread guides 11 (Fig. 23), 12, from top to bottom they are threaded into the holes of the thread guide square 13. One thread is passed in a clockwise direction between the washers of the tension regulator 14, the other counterclockwise - between the washers of the tension regulator 17. Further both threads clockwise are inserted into the groove of the regulator 15 and from bottom to top they are brought under the thread take-up spring 16, they are passed under the lamellar thread guide 9 and from right to left they are threaded into two eyes of the thread take-up 10. The threads are guided down the sub-lamellar thread guides 9, 8, into two holes on the needle holder 7 and from the side of long grooves facing each other, thread into the ears of needles 5, 6. Lower

Figure 22. Machine 852 (× 5) cl. PMZ

the threads are wound on two bobbins, as in the machine 1022-M cl. OZLM. Then one bobbin 1 with the latch 2 raised is inserted into the bobbin holder 3. When the loops of the lower threads are pulled out of the holes in the rack, the threads are tightened under the leaf springs 4. The second bobbin is done in the same way. Adjusting the needle mechanism. The height of needles 1 (Fig. 24) relative to the hooks tips is adjusted by vertical movement of the needle holder 2 inside the hollow needle bar 5 after loosening the tightening screw 3 of the adjusting ring 4. The position of the needles 1 relative to the walls of the holes in the rail is adjusted by turning the frame 6 and the upper shaft 7 after loosening the tightening screw 8 rocker arms 9. Adjustment of shuttle and drain mechanisms. The timing of the approach of the shuttle noses to the needles is adjusted by turning the shuttle shafts 13 (Fig. 25) after loosening two stop screws 11 of the gear 12. When lifting the needles from the lowest position by 2 mm, the noses of the shuttles should be 1.6 mm higher than the ears of the needles. The gap between the needles and the hooks noses, which should be equal to 0.05-0.1 mm, is adjusted by moving the cases 3 along the shaft 16. To perform the adjustment, loosen the screws 14 of the gear wheels 15, the screw 8 for fastening the croutons 7, 19 and the screw 4. Then move the crankcase together with the gear wheel 15 along the axis of the shaft 16. Timeliness of movement of the spool holders \\ 7 for pressing on the protrusions of the bobbin holders is achieved by turning the shafts 20 after loosening the screws 6 of the gear wheels 5. The steppers 7 must press on the protrusions of the bobbin holders at the time of inserting the needle loops into the shuttle sets, that is, create a gap between the fingers of the bobbin holder and the groove walls of the throat plate. The position of the diverters 17 relative to the protrusions of the bobbin holder is adjusted by moving them along the groove of the levers after loosening the screw 18. The amount of oil supplied to the shuttles is adjusted by screws 10 after loosening the screws 9. If the screw 10 is screwed down, the amount of oil supplied to the shuttle will decrease. Also regulated

Figure 24. Machine needle mechanism 852 (× 5) cl. PMZ

oil supply to the couplings of the drain links. The tension of the lower threads is adjusted with a screw 1 due to the deformation of the leaf springs 2. To change the distance between parallel lines, replace the needle holder, foot, rail, stitch plate; the crankcases 3, together with the gear wheels 15, are moved along the axis of the shaft 16, as when the gaps between the needles and the shuttle tips are changed. Adjustment of the material transfer mechanism. The stitch length is adjusted by turning the lever 17 (Fig. 26) relative to the scale 18 after screwing in the nut 20. If the lever is turned counterclockwise and its position is fixed with the stop 19 by unscrewing the nut 20, the stitch length will increase due to the turn of the frame 22 counterclockwise. To secure the line, the worker presses on the handle 21, which makes the lever 17 turn clockwise. This will cause the material to move towards the worker. The lifting height of the rack 7 above the stitch plate is adjusted by turning the rocker arm 10 on the lift shaft 11 after loosening the tightening screw 9. The horizontalness of the teeth of the rack 7 is adjusted by its vertical displacement using

Figure 25. Shuttle and diverter mechanism.

screw 5 after loosening screws 8, 6. Timeliness of raising the rack 7 and timeliness of material movement are adjusted separately by turning the eccentrics 12, 15 after loosening the screws 13, 16 or by turning the main shaft of the machine. At the moment the needles pierce the material, the rail should begin its movement. The position of the rail 7 in the slots of the needle plate is adjusted by turning the rocker arm 3 after loosening the screws 4 on the displacement shaft 2, if the rail is to be moved across the platform. To move the staff 7

Figure 26. Mechanism of the engine tissue machine 852 (× 5) cl. PMZ

along the platform, screws 4, 9 are loosened and the rocker arms 3, 10 are moved along the shafts 11, 2. The equality of stitch lengths during forward and reverse movement of the rack 7 is adjusted by turning the frame 22 after loosening the screws 1. The tension of the spring 14 required to return the lever 17 to its original position after securing the stitch, it is adjusted by moving its threaded hook 23. Adjusting the foot assembly. The pressure of the foot 1 (Fig. 27) on the material is adjusted by the screw 7 due to the deformation of the leaf spring 5 relative to the axis of the square 6. If the screw 7 is unscrewed, the pressure of the foot will increase. The lifting height of the foot 1 above the stitch plate is adjusted by vertical movement of the clutch 3 along the rod 2 after loosening the tightening screw 4. If the clutch 3 is lowered, the presser foot 1 will rise by a large amount. The position of the arms of the presser foot 1 in relation to the line of movement of the needles is adjusted by turning the rod 2 after loosening the screw 4. Adjusting the bobbin winder. The number of threads wound on the bobbin is adjusted by vertical movement of the stopper 12 after loosening the screw 11. If the stopper 12 is moved upward from the axis of the spindle 13, the number of threads on the bobbin will increase. The engagement of the gearwheel 8 teeth with the winder gearwheel is adjusted by the axial movement of the gearwheel 8 after loosening the screws 9 along the main shaft 10. The uniformity of thread winding on the bobbin is regulated by turning the thread guide 14 after loosening the screw 16. The tension of the threadwhen winding on the bobbin is adjusted by the nut 15.

Figure 27. Machine foot assembly 852 (× 5) cl. PMZ

3.14. Button semiautomatic device 1095 class.

Class 1095 semiautomatic device is the basic design. From a technological point of view, it is universal: it is possible to sew flat buttons on it in various ways close to the fabric and on the "leg"; close to the fabric with a button and on a "leg" with a button; blind stitches. Sewing on with different diameters and different hole spacing is possible.

Technical characteristics of the semiautomatic device

Table 4

The composition of the semiautomatic device

The semiautomatic sewing head consists of the following mechanisms and devices:

The mechanism of vertical movements of the needle and thread feeder;

Looper mechanism;

Spreading mechanism;

Mechanism of the engine of the fabric and the button holder;

Needle deflection mechanism;

Auto-stop node;

Thread trimming unit;

Assembly for lifting the button holder and thread diverter;

Thread clamping mechanism when trimming;

Devices for winding the thread from the bobbin and adjusting its tension.

The movement of the materials to be processed occurs due to the movement of the teeth located in the lower plate, and the pressure of the foot. The initial setting of the sewing machine at the factory is carried out to work with frequently used medium-weight fabrics: linen, cotton, gabardine.

Needlewomen are not limited to sewing products from such materials, especially since modern units can work with canvases of different densities. For example, when sewing on thin seams, it is undesirable for the presser foot to press too hard, otherwise puffs may appear on the fabric. Knitted fabrics are stretchable, so excess pressure will cause elongation in the seam area.

Working with high-density canvases - canvas, on the contrary, it is necessary to increase the pressure so that sufficient frictional force arises, contributing to the normal movement of the parts to be sewn.

Why is it important to adjust the pressure of the foot?

Every dressmaker should understand for themselves that a sewing machine is a mechanism that needs to be adjusted in order for the work performed to look neat. The installed feet are made of different materials: metal, plastic, teflon. They will slide on the fabric in different ways, so the pressure must be adjusted to ensure uniform advancement of the parts to be sewn. It depends on how uniform the stitches will be.

If in mechanical models the seamstress's foot pressure was adjusted manually, then in modern models a regulator is already provided on the body. An experienced dressmaker first adjusts the equipment, conducts trial operations on an unnecessary piece of fabric, and then starts work.

How to reduce the presser foot pressure in mechanical sewing machines?

Old-style devices consisted only of metal parts: assemblies, parts, body. Therefore, in order to increase or decrease the force with which the foot presses on the fabric, it was necessary to rotate the screw located on the shaft. Due to this, there was an adjustment: compression or extension of the spring, which exerts pressure.

Finding the rod is easy. In older models of the "Podolskaya" type, it comes out into the hole located in the upper part of the case. In units with an electric drive, you need to remove the top cover, under it, in the sleeve, all the main components are located.

Adjusting the foot pressure in modern machines

Electromechanical devices are arranged a little differently. You don't have to find the shaft of the foot. Many models have a regulator that makes it easy to adjust the pressure of the presser on the fabric. It is located on the machine body or under the front panel cover. How to make the setting is described in the instructions.

In computerized models, such a regulator, as a rule, is absent, since the device itself adjusts the necessary modes based on the installed program.

Therefore, when deciding whether it is necessary to adjust the pressure of the foot in the machine before sewing, study the principles of operation of the device, read the instructions carefully.