How to raise the foot on the janome sewing machine. How do I set up my sewing machine for different fabrics? What are the paws

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

A regulator for the pressure of the foot on the fabric was a standard option 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 for the presser foot on the fabric?

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 be influenced by the pressure of the foot.

The foot can be made of various materials - chrome-plated steel, plastic, Teflon. Accordingly, different legs will slide on different materials with different amounts of friction force. Another factor is tissue distortion when the fabric is pressed against the feed teeth. It is necessary to select the optimal presser foot pressure so that the fabric is fed efficiently under the needle by the feed dog and so that the fabric does not deform when it is 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 will glide optimally on the selected fabric. So choose a clipper with a presser 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 don't think about anything, you don't 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 get 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 gets even worse, then do the opposite - decrease the pressure of the foot.

The mechanism of the foot is an integral part of the mechanism of the fabric motor 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 head of the machine. A bracket 18 is freely put on the sleeve from above, 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 by 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 arm body. The right arm of the lever 10 is connected to a rod 12, the position of which is fixed with 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, and abuts against the cotter pin 14.

A guide 7 is fixed on the rod 2 with a tightening screw 18, the outgrowth 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 the 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 presser 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 presser 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, together with the rod 2 and the tab 1, rises. 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 pusher 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 throat 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 the 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 pressure chamber 12.

On 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 = 7: 1.

When the camshaft rotates, the worm pair transfers the 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 pipe 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, oil flows to 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 through the pipe 18 is sucked in by the pump chamber 11 (Fig. 20, a) and is forcibly drained into the sump.

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 directed to the gears of the shuttle mechanism. Through pipes 15 and 26, the oil enters the cracker of the rack lifting shaft and into the hinge joints of the frame 14 of the shaft 16 of the fabric motor assembly.

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

The shuttle mechanism is also forcibly 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 bore of the shuttle shaft 33 spreads in two directions. Moving to the left, the oil along the wick Ф 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 comes out into 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 cross-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 machine 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 intended for sewing with two parallel shuttle weaving lines of linen, suit, raincoat materials made of natural and mixed fibers (fig. 22). The peculiarities of the machine are that the needles, in addition to vertical movements, deviate along the lines; Central bobbin shuttles are used, rotating in the 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 the two ears of the thread take-up 10. 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 the 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 drainage 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 nose, which should be equal to 0.05-0.1 mm, is adjusted by moving the crankcases 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. The timing of the movement of the spool holders \ 7 to press 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 the screws 10 after loosening the screws 9. If the screw 10 is tightened, 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 diverter 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, causing the lever 17 to rotate clockwise. In this case, the material will begin 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 to move. The position of the rail 7 in the slots of the stitch 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 motor of the fabric of the 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 presser 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, then the presser foot 1 will rise by a large amount. The position of the arms of the presser foot 1 relative 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 the 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 adjusted 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. The unit of the presser foot of the machine 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 versatile: it can be used to sew flat buttons 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;

Cloth motor and button holder mechanism;

Needle deflection mechanism;

Auto-stop node;

Thread trimming knot;

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 processed materials 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 that the pressure on the presser foot is too strong, otherwise puffs may appear on the fabric. Knitted fabrics are stretchable, so excess pressure will cause elongation in the seam area.

When working with high-density canvases, canvas, it is necessary, on the contrary, to increase the pressure so that a sufficient frictional force arises, contributing to the normal advancement 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 so that the work performed looks 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, in modern models a regulator is already provided on the body. An experienced dressmaker first sets up 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 and all the main components are located.

Adjusting the presser 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 the device, read the instructions carefully.

Hemming foot is an optional accessory used to trim the edges of the fabric. The accessory helps to save time and effort on hand overcasting, marking, ironing, etc. Usually this model of the foot is included in the standard sets of accessories for sewing machines, but only in one size. If necessary, you can order the desired option on a specialized website or in a store.

What are the paws

The presser feet are not considered the most important part of the sewing machine. But it is this device that allows you to make a neat stitching, which will not only securely hold together the details of the product, but also make it more original.

Usually the presser feet are included in the sewing machine accessory kit. The more expensive the model of the device, the more legs. But not all of them are equally needed when sewing. Standard sets always include a universal foot for straight and zigzag stitching, hemming and button sewing. The rest of the legs can be purchased.

When choosing a specific model of the foot, you need to understand for what purposes it will be used. For everyday needs, a standard set is usually enough, but for the implementation of creative ideas you may need a special foot.

Hem (hemming) foot: features and functionality

All sewing feet and their use with photos will not be described in detail here. Different sites use different names for the hemming feet (hemmers) for the sewing machine. It can be referred to as a twist, hem or hem, hem, or hemming foot. Slightly less common are the names "cutter", "cutout". Regardless of the name, however, this accessory will work the same way.

Like other types of accessories, hemming feet from manufacturers Janome, Brother, Jaguar, Singer 52 may differ in shape, material quality, cost. So you need to choose a specific model based on what type of fabric you need to hem, what skills the seamstress has, how much work will have to be done.

A distinctive feature of the hemming foot from the usual one is the presence of a special curling device located on the front of the accessory. It is it that allows you to carry out several operations in a minimum of time, which, in the absence of a foot, would have to be performed manually. Such a device is called a "snail". It turns sewing into a creative process that takes a minimum of time and effort. And all because in one full cycle of work, the "snail" makes two folds of the fabric, which immediately fixes in the desired position with the help of a neat seam.

Like the foot, the resulting seam can be called differently: narrow hem, American seam, Moscow seam, narrow hem. The essence does not change from the name - the line turns out to be smooth, beautiful and reliable. This is ensured by the special design of the curling device. In front there is a guide piece that catches the edge of the fabric without deforming it. If this were not the case, the material would periodically slip out from under the foot. This is especially true for lightweight fabrics such as silk, chiffon, satin.

Hemming feet are included as standard accessories, but only in one form. For most of the most common operations, this is sufficient. But for more complex tasks, you may need an accessory of a different size.

Different models of the presser foot can be used for overcasting 2, 3, 4, 5 and 6 mm widths. It is of this size that the fold is obtained.

The feet can be metal or plastic. Both options perform the same function - just put the foot in the machine and you can sew. Metal lasts longer, therefore more expensive. But the use of plastic is more convenient, since you can visually control the direction of the line. This avoids interruptions and saves time and effort in reworking the seam. However, plastic paws are considered less reliable, as they often break and scratch if sewing carelessly (the needle periodically sticks into the foot, so it can break or bend).

How to use

Undercutting foot: how to use. The algorithm for using the device is simple. It provides:

Selects the straight stitch mode.
Cutting off a small edge of the material at an angle from the side of the cut to be cut.
Threading the cut-off corner of the fabric into the hemming foot.
Installing the presser foot in the sewing machine using a special presser foot holder.
Lowering the presser foot, sewing a few stitches with both threads to the back (the cut of the fabric should roll up and go through the hem hole on the accessory).
In the future, the material should be fed at an angle of 90 degrees relative to the working surface of the sewing machine.

There are no difficulties in this algorithm. However, in the absence of sufficient experience, they can occur at any stage of sewing.

Here are a few things to remember before using the custom hemming foot.

Experienced craftswomen advise to use threads ### 120, 150 during the processing of the edge of the material. To do this, you need a thin needle —No. 70 or 80. The stitches of the stitch should be 2.5-3 mm long. If you need to hem the edge of a thin material, you can pre-treat it with starch.

The main difficulty in working with this foot is threading the fabric into the "snail". An overview of several methods is outlined below.

The easiest way. First you need to cut off a small corner of the fabric. This is done at an angle of 45 degrees in relation to the material so that a right-angled isosceles triangle is obtained. The length of both sides of the triangle should be twice the width of the hem that the foot is designed to handle. If it is designed for 2 mm, a piece with sides 4 mm long is cut from the edge of the fabric. Along this edge, the material must be folded over a distance that is twice the final hem (in this case, 4 mm). And only after these operations can the material be wrapped in the switch foot.

When sewing, you need to advance the fabric under the foot with the edge bent to the desired width (it corresponds to the size of the foot). In this case, the fold line on the fabric should coincide with the line on the right side of the foot (it goes along the right side of the frame with the "snail").

One more nuance. It is necessary that the distance between the working surface of the machine and the clearance of the raised presser foot is sufficient for the operation. When the fabric is on the foot, secure it by lowering the sewing machine needle. Next, the foot is lowered and the first stitches are made.

Second way. On the edge of the piece of fabric to be processed, make 3-4 straight stitches on the machine. The stitch length is 2.5-3 mm. The stitch should be done at a distance from the edge to be sewn, which is half the width of the hem for which the foot is designed. For a 2 mm foot, this distance corresponds to mm. But it is better to make this distance a little larger, as the fabric may begin to crumble. Next, lower the needle and sewing machine foot and start sewing. You need to slowly insert the fabric into the foot so that the stitching is neat and even.

Third way. The edge of the fabric must be tucked in twice to a distance that corresponds to the size of the foot (if the foot is designed for 2 mm, then two folds should be 2 mm each). The folded edge of the fabric is positioned under the foot. The fold in the fabric should match the snail frame line on the foot. Next, the needle and the foot are lowered, and along the fold of the bent material, 3-4 straight stitches 2.5-3 mm long are made on the machine. Then the foot must be raised and the needle remains in the down position to hold the fabric. The released edge of the material is pushed into the curling device of the foot, the foot is lowered and, keeping the corresponding width of the manual hem, a seam with a hem is made.

There are many recommendations on Youtube on how to use the switch legs. However, each seamstress may give different advice as she gains experience. For beginner seamstresses, experienced craftswomen advise using plastic devices. They break more often, but the seam is always visible and you can correct the situation in time. When working with different fabrics, it is better to opt for the metal foot, as it is more durable and durable. If the foot is used not for production purposes, but for household needs, one device from the standard set is enough.

Another important detail is that the ways of attachment to the foot holder may differ from the switch feet from different manufacturers. In some cases, you will have to purchase an adapter - a special adapter that is installed to secure the device more securely. So when buying this model, it is better to come to the store with any foot from the machine, so that the consultant can check if the mount is suitable, or at least grab a photo of the foot.

A zigzag stitch is suitable for hemming 5-6 mm wide, while for others it is better to sew it with straight stitches.

More information on how to use the switch foot can be found in the video below.

January 18, 2012

The rail works with a presser foot, which must press the fabric against the rail with a certain force over its entire area. For this purpose, the presser foot unit has an adjustable spring, as well as parts with which the presser foot is raised and lowered onto the fabric.

The presser foot can be with a movable sole and with a swinging one on a hinge. Such legs are convenient in that they allow you to easily pass thickened places. The presser foot unit has the following arrangement.

a - foot knot,
b - kinematic diagram of the foot assembly:

adjusting screw,
spiral spring,
branch of the muff,
spring-holder,
lever arm,
rod,
rod,
presser foot.

The presser foot 8 is screwed to the rod 7. Above the spring holder 4, a spiral spring 2 is put on, on which the adjusting screw presses from above. Under the action of a spring, the foot presses on the fabric, the clamping force can be changed with the adjusting screw. If the screw is turned to the right, the spring compresses and creates more pressure on the fabric, and vice versa.

To raise the foot in the machine head, a lever 5 equipped with a cam is connected by a hinge screw. If you turn the lever and bring its cam under the lateral process of the clutch 3, then the clutch will rise and raise the foot rod and the presser foot.

The transformation of the rotary motion of the main shaft into the oscillatory motion of the shuttle is carried out using the shuttle mechanism.

a - shuttle knot,
b - kinematic diagram of the shuttle mechanism:

crank,
connecting rod,
swinging roller,
fork,
slider,
shuttle shaft,
clip with shuttle.

The movement of the main shaft by means of the connecting rod 2 is converted into the oscillatory movement of the oscillating roller 3. The oscillating movement from the roller is transmitted to the slider 5 inserted into the fork 4 of the oscillating shaft. The slider moves in the fork and drives the shuttle shaft 6. At the left end of the shuttle shaft there is a holder where the shuttle 7 is inserted. When the oscillatory motion is transmitted from the swinging roller to the shuttle shaft, the angle of rotation of the shaft increases.

The thread take-up mechanism feeds the thread and tightens the stitch. The roller 3 of the thread take-up lever slides into the groove 4 of the cylindrical cam 5.

a - mechanism node,
6 - kinematic diagram of the thread take-up mechanism:

main shaft,
lever arm,
video clip,
cam,
eyelet,
hinge screw.

Lever 2 is reinforced with a hinge screw 7 in the hole 1 of the machine sleeve, and its shoulder, which has an eyelet 6 for passing the thread, protrudes from the slot of the front board.

When the cam rotates, the roller slides along the groove and drives the thread take-up lever, which moves up and down at variable speed and participates in the stitch formation process - slowly feeds the thread and moves down, quickly rises up and tightens the stitch.

Questions

What are the working bodies, what is their purpose?
What mechanisms of the sewing machine are used to convert rotary motion into reciprocating motion?

"Serving Labor", S. I. Stolyarova, L. V. Domnenkova