1, classified by purpose
There are three kinds of sewing machines: household sewing machines, service sewing machines and industrial sewing machines.
2. Classification by stitch
It can be divided into single-line lock stitch, double-line lock stitch, single-line chain stitch, double-line chain stitch, multi-line edge chain stitch, three-line wrapped stitch, double-line compound chain stitch, hand-like stitch and wireless stitch.
3, according to the hook mechanism classification
It can be divided into swing hook, rotary hook, single curved needle hook, double curved needle hook and rotary hook.
4, according to the thread pick mechanism classification
There are seven kinds of thread take-up: needle bar thread take-up, cam thread take-up, connecting rod thread take-up, sliding rod thread take-up, double-acting swing rod thread take-up, rotary thread take-up and gear thread take-up.
What is the sewing principle of sewing machine?
The core of sewing machine is the coil sewing system, and its coil sewing method is very different from ordinary manual sewing. On the machine needle, the eye of the needle is behind the needle tip, not at the end of the needle. The sewing machine only needs to pass the needle part through the cloth, the needle is fixed on the needle bar, and the needle bar is pulled up and down by the motor through a series of gears and cams. When the needle tip passes through the fabric, it pulls a small coil from one side to the other. A device under the fabric will grab this coil and then wind it on another thread or another coil of the same thread.
The simplest loop needle is a chain needle. To sew chain stitches, the sewing machine will loop the same length of thread behind the thread. The fabric is placed on the metal plate under the needle and fixed with the presser foot. At the beginning of each sewing, the needle pulls out a loop through the fabric, and a device for manufacturing the loop grasps the loop before the needle is pulled out, which moves in synchronization with the needle. Once the needle is pulled out of the fabric, the cloth feeder will pull the fabric forward. When the needle passes through the fabric again, the new loop will pass directly through the middle of the previous loop. The equipment that makes the coil will grab the wire again and make a coil around the next coil. In this way, each coil will fix the next coil.
The main advantage of chain sewing is that it can be sewn quickly, but it is not particularly strong. If one end of the thread is loose, the whole sewing may be loose. Most sewing machines use a stronger stitch called lock stitch.
The most important parts of sewing equipment are swing hook and spool assembly. A bobbin is a winding wire placed under a fabric. It is located in the center of the shuttle, which is driven by a motor and rotates synchronously with the movement of the needle. Like chain sewing, the needle pulls out a loop through the fabric, and the cloth feeder moves the fabric forward, and it rises again and then puts in another loop. However, this sewing mechanism does not connect different coils together, but connects them with another wire that is loosened from the spool.
What parts does the sewing machine have?
General sewing machine consists of four parts: head, frame, transmission and accessories. The nose is the main part of sewing machine. It consists of four mechanisms: piercing, hooking, picking and feeding, and auxiliary mechanisms such as winding, pressing and tooth dropping. All mechanisms work in a reasonable and coordinated way, working in cycles, and sewing materials.
The frame is divided into two forms: bed board and chassis. The bed plate of the bed plate frame plays the role of supporting the machine head and is used as a workbench during sewing operation. There are many styles of bed boards, including one or more bucket folding, cabinet type, desktop type and so on. The chassis of the chassis frame plays the role of supporting and storing the machine head, which makes the sewing machine easy to carry and keep.
The transmission part of sewing machine consists of frame, hand crank or motor. The frame is the pillar of the machine, supporting the base and pedals. When in use, the operator steps on the pedal to drive the pulley to rotate through the crank, and then drives the machine head to rotate through the belt. Most hand cranks or motors are directly mounted on the nose.
Accessories of sewing machine include needles, spools, screwdrivers, oil pots, etc.
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