Device and principle of operation of a sewing machine
Initially, the device of the sewing machine was developed as follows, so that she can do the work herself, thus replacing man. This invention has greatly facilitated the work of seamstresses, and increase its productivity. The scheme of work allows even an absolute beginner, who never held a needle in her hand, sew straight and high-quality trails. The latest generation of devices sews not only in a simple way, they are able to create patterns and embroidery. The achievements of modern technology are impressive, but the principle of operation of each sewing machine is still based on the same first algorithm, developed many years ago.
Scheme of the device of the sewing machine
There are basic parts of a sewing machine, without which no unit is complete:
- flywheel;
- winder;
- sleeve;
- sewing platform;
- stitch selection wheel;
- hose rack
- receiver (reverse)
- needle holder;
- golkov plate;
- foot;
- lever for raising and lowering the foot.
But these are the details, which are visible at superficial inspection - they are a small part of the mechanism hidden under the case. There is a complex system inside to operate the shuttle. We can say, that the operation of the sewing machine is entirely based on the shuttle device. To the untrained person, the details of a regular sewing machine may seem complicated and confusing, but everything becomes clear, if you understand a little.
Coil
The coil is the most noticeable detail, from which the tailor is in constant interaction. It is located behind the sliding panel under the needle. To get the coil out of the socket, pull it on yourself and a little up. This will drive away the small grip and release the item.
The spool is needed to supply the threads, which before work on it are wound from the main coil. This happens automatically - the thread from the spool is pulled into a special hole in the spool. After that, the part is placed in the nest, and the spool of thread is fixed on the body of the machine. When the flywheel is activated, the coil rotates, which winds the thread on its axis, the spool of thread also rotates.
To tension the thread during operation, the structure of the spool includes a small screw. Properly set settings eliminate the possibility of skipping the upper and lower stitches. The tailor can sew, without being distracted by constant quality checks. Carefully check the thread before starting work, its excessive tension causes constant breaks. Watch a video about the perfect thread tension.
A small detail, the so-called spout, designed to insure the coil against accidental coil drop. It is mounted on a moving panel, which is squeezed by a spring mechanism from the housing of the sleeve. If everything works, as intended, then the system does not crash. While this part is in the correct position, the coil is securely fastened in the sewing machine and cannot be removed. To perform the reverse assembly, bend the spout, and, holding it in this position, insert the spool in place.
When studying the body on a sewing machine, you can find an elongated protrusion. Its task is to prevent the rotation of the coil with the coil or the shuttle drive.
shuttle
Inserted ??in place the coil interacts with one of the main parts of the device, namely with the shuttle. It is presented in the form of moving back and forth details, cut on a special profile.
A working sewing machine drives it with a connecting rod, which sets the correct trajectory.
The operation of the connecting rod connection can be controlled by the operator. For this purpose on the case the sliding metal panel is specially provided. Unscrewing it, can be seen, how the flywheel rotates, driving the needle, that goes down, then up. At the point of ascent, less than five millimeters from the table surface, a sharp admiration passes by her.
This grip is the bow of the shuttle. The device of the sewing machine provides a gap between this spout and the needle, not very big, but not small enough, to allow their accidental collision.
Sometimes the distance begins to increase, and if its value changes by at least half a millimeter, then the machine will start skipping stitches in a row. In this case, the needle continues to work, the fabric moves properly, but the thread completely stitches it. Perforated ??matter is practically not fastened together and continues its movement. To eliminate this problem, it is necessary to adjust the position of the needle to the shuttle.
Video about it, how to adjust the shuttle of a sewing machine from the company "Podolsk".
Operation of a sewing machine
How is the sewing machine arranged, and what forces activate its internal processes? At the heart of the whole system is the simplest principle, based on a given needle movement. Capturing the upper thread, she slips it down. Then she is picked up by a boat ready for this, and interweaves the lower with the upper thread.
The simplest movement provides the basis for such complex manipulations, as tortuous seams and even patterned embroidery. Video about it, how to embroider on a home sewing machine.
Manufacturers are improving their models. Today there are units with a special application in the form of a side needle for processing the edges of the fabric, however, finding them in simple stores is not easy.
The inner part of the case hides the drive, which is operated manually (in mechanical machines) or by means of an electric motor (in electromechanical devices). The engine uses a connecting rod to start the rotation of the other three shafts. If you go into details, we can say that the system includes one intermediate axis, which transmits the rotational momentum to the three described shafts.
This system is designed for a long period of use and is considered quite durable. Holes are provided in the housing for the application of lubricants to the moving parts, in which the nose of a buttercup can easily pass.
Mechanisms of mechanical sewing machines are not subject to rapid wear, and their characteristics are considered one of the best. Properly covered, it will withstand a great deal of adverse conditions for up to 50 years, without any problems. However, this requires that you follow all the instructions for cooking before work, as well as regularly lubricate and clean moving parts
In more advanced models, a pedal is provided, when you press the foot on which all the mechanisms are set in motion. It is much easier to use, as it gives freedom of hands. Of course, modern designers have improved this system, turning the pedal from mechanical to electrical.
moving tissue
Speaking of which, how a home sewing machine works, the description of the device cannot be omitted, intended for stretching matter. This revolutionary invention for its time allowed to set the desired length of stitches, and relieved tailors of the obligation to monitor the progress of the flap.
Everything happens as follows:
- at the first stage, along the central part is the main shaft, which connects to the flywheel axis via a connecting rod;
- in the lateral parts are two rods, at synchronous rotation of which the long mechanism comes into motion.
The first is completed with a detail, which experts call each other "swallow's tail". For an ordinary person, it is more like a key. This element moves back and forth in the direction of the fabric.
A cam is provided in the second axis, which is located in the space "swallow's tail". Its main function is the rise and fall of this part.
The final result of all the movements of these mechanisms is the work of the sewing machine, detail in the form of a "swallow's tail" gives movement to the long teeth. Receiving momentum, teeth perform their steps, scrolling in place.
All manipulations to adjust the length of the stitch is carried out using a rotary lever. A very small detail is fastened to the axis of the tail key. When turning the lever, the tails change their configuration from the starting position, which changes the stitch length in the row. The video shows, how to properly adjust the length of the steps.
thread tension
This manipulation is performed using a special screw, located above the needle holder. The tension of the upper thread is an important indicator, which controls the quality of the seam. Not far from the needle holder is a special lug, which moves in the course of work and does not allow the stretched thread to weaken or sag, when the needle goes up. Without this little detail, all the work of the sewing machine would be nullified.
Video about it, how to assemble and install the thread tension adjuster.
winding device
At the end of the description it is necessary to say a few words about the winding device. Usually, near the flywheel for winding is a small clamping wheel with a shaft, complete with risk.
On the panel, located below it, there is an eyelet with another small wheel. The coil is mounted on a vertical stand, and from it the thread is passed over a table, to be wound on a spool. To ensure proper operation, the clamping wheel is gently pressed with a finger, after which the rotation begins, transmitted from the drive of the sewing machine.
The design provides another option. If the bottom thread suddenly ends, you can use the end, taken directly from the needle. The main thing, do not forget to remove it from the ear beforehand. Then repeat the algorithm described above.
