The structure of the machine. Appearance is all-needle sanding machines have many similarities. The machine consists of a platform 1 (Fig. 3), the sleeve 2, the head 3, the flywheel 4.

The sleeve machine is a main shaft that receives motion from the flywheel and transmits motion to other working bodies of the machine. In the machine head are placed the details of the mechanisms of the thread take-up lever, needle and presser foot. The front of the machine head closed the front Board, which protects the mechanisms from contamination. The machine head is the regulator tension of the upper thread. Inside the rack and under the platform of the machine are the parts that transmit the movement of the Shuttle and feed. The slot in the platform above the hook and the motor tissues closes the needle plate. 

These machines stitch is formed in the following way. The needle pierces the fabric and carries the thread through them. Along: needle has two grooves (grooves) to reduce the loss of strength of the threads: one of them placed the thread when passing through tissue. When moving the needle up to 2.5 - 3 mm from the short groove formed by the overlap of a loop. This loop captures the hook (hook mounted on the Shuttle shaft), it expands and encircles around spiderites inside the Shuttle. Spidergate is placed in the bobbin case with the bobbin. Spidertel secured a special trim ring.

Once the loop is encircled hook more than half of the bobbin, the work included the thread take-up lever, oscillating up and down (in the car, 22-PMZ class), provided with a lug, which fueled the upper thread (in the car 97 CL. OSL applied uniformly rotating thread take-up lever Cam type for smoother tightening of the stitch without any sudden tension of the thread). At the time of the bypass loop around spiderites thread take-up lever is lowered slowly, feeding the thread to the Shuttle, then quickly rises and tightens the stitch.

For the formation of a single stitch, the hook makes two revolutions: in the course of working loop is encircled around spiderites, at idle be a tightening stitch and a new puncture needle tissue. The feed moves the fabric along a line while tightening the stitch to the moment of approach of the needle to the fabric to make a new puncture.

 The advantages and disadvantages of Shuttle lines. Line Shuttle stitches has a number of positive properties compared to the chain: she is not dissolved, has a beautiful appearance and require a small amount of thread in the formation of stitches.

The disadvantages of the line are: somewhat reduced strength of the upper thread (15 - 20 %) as a result of repeated friction of it on the eye of a needle, fabric and details in the process of formation of the stitch; insufficient elasticity for stitching highly stretchable sections (oblique sections of fabric, knitted cloth, etc.). 

 Refilling and adjusting the tension of the upper and lower threads. Top thread all sanding machines run almost the same (Fig. 4). From the coil or bobbin, is located on the sleeve of the machine or on bunoderidae, the thread is carried out through a system of yarn guides. The guides change the position of the thread from horizontal to vertical and feed it to the Adjuster between the spiral spring and two metal discs. Further, the thread having a spring that compensates for an excessive supply of thread, and nitroprusside of polynices, then it enter from right to left into the eyelet of the thread take-up lever.After that, the thread having two guide wire on the front Board, which prevent the rocking of the skin and protect it from breakage, then to the Director under osloboditelen in the eye of the needle from right to left, i.e. from the side of the long groove. Proper dressing and good quality threads ensure smooth operation of the machine.

The tension on the upper thread adjust using the Adjuster located at the head of the machine. The tension of the lower thread is regulated by the screw of the leaf spring on the bobbin case cap. When screwing the screw, the tension increases when unscrewing decreases.

The correct tension of the thread in line check by stretching lines in transverse and longitudinal direction. If the tension of the thread in the stitching is correct, then after stretching the seam in the transverse direction of the seam takes the former view. If the wrong tension thread seam after the transverse stretching remains with visible thread lines. When checking the tension of thread in the longitudinal direction of the seam to stretch along the line, it is necessary that the line was not disrupted and remained the strength of the thread. 

 The frequency adjustment of stitches and presser foot pressure. The number of stitches in 1 cm, referred to as frequency lines, installed during the manufacture of clothing, depending on the purpose and type of stitch or stitches. Frequency adjust lines special screw, located on the front of the sleeve sanding machine. To do this, press lever reverse, lightly pull the screw on and turn off, setting the desired stitch length is shown in mm on the screw head.

For proper machine operation it is necessary that the foot pressed the fabric to the needle plate with a force of 3.5 to 4.5 kgs. At low pressure the presser foot the cloth is not going to move; it rises with the needle that may cause skip stitches. Under strong pressure the presser foot heavier machine operation and may occur Pribivanie tissues.

The necessary presser foot pressure set by rotating the adjusting screw, located on the machine head. To increase pressure the feet have to tighten the adjusting screw to decrease unscrewing. Foot pressure must correspond to the type and properties of the processed tissues: hard tissues of the foot pressure increase, the thin and soft - save. 

 Installation of a needle. Normal operation of the sewing machine, good quality stitching is largely dependent on the proper selection of needles and its mounting in the car. Needles are chosen according to the type of machine, processed fabric and number of threads. When you install the needle flywheel turning machine so that the needle bar has occupied the top position. Then slightly Unscrew the screw of the needle bar and insert needle into the clamp (needle holder) to stop short groove to the sleeve of the machine. Then fix the needle screw.