How Electric Sewing Machines Work

A sewing machine is a machine that uses one or more sewing threads to form one or more stitches on the sewing material, so that one or more layers of sewing material are interlaced or sewn together. The sewing machine can sew cotton, linen, silk, wool, man-made fibers and other fabrics and leather, plastic, paper and other products.

In 1790, St. Thomas in England invented a hand-operated sewing machine with single-thread chain stitch for sewing boots and shoes. This sewing machine is made of wood and some parts are made of metal materials. It is the first sewing machine in the world.

In 1841, Timonnier of France designed and manufactured a practical double-thread chain stitch sewing machine; in 1846, Howe of the United States obtained a patent for a curved lock stitch sewing machine with a sewing speed of 300 stitches per minute and an efficiency of more than five. Hand-operated seamstress; In 1851, the American mechanic Singer independently designed and manufactured the Singer sewing machine with a sewing speed of 600 stitches per minute, and obtained a US patent in 1853. Since then, sewing machines have been used in large quantities for production, and functions such as buttoning, buttonholes, reinforcement, and embroidery have been gradually added.

In 1975, the United States invented a microcomputer-controlled household multi-function sewing machine.

The development of industrial sewing machines is more extensive, and the sewing speed is getting higher and higher. For example, the overlock sewing machine has reached 10,000 needles per minute. In 1979, the total output of sewing machines in the world reached 15,885,000 units, of which China's output was 5,870,000 units, making it the country with the largest sewing machine output in the world.

There are many classification methods of sewing machines, and the most common is to distinguish them according to stitches and uses.

The stitches of sewing machines can be classified into two categories: lock stitches and chain stitches. The lock stitch is common and consists of two stitches that are intertwined like a twisted rope, and the interlacing point is in the middle of the seam material. From the cross-section of the stitch, the two stitches are like two locks locked to each other, so they are called lock stitches.

This stitch is used for sewing materials such as cotton, wool or leather with low shrinkage. The front and back sides have the same shape, like a dotted line. The stitches are densely distributed, and the sewing fastness generally exceeds that of manual sewing.

Chain stitches are self-connected or interconnected by loops of sutures. Commonly used are single-thread chain stitches, double-thread chain stitches and three-thread overlock stitches.

The characteristic of this stitch is that the stitch is elastic, and it can expand and contract with the sewing material without breaking the stitching.

General sewing machines are composed of four parts: head, base, transmission and accessories.

The machine head is the main part of the sewing machine.

It is composed of four mechanisms: barbed material, hook thread, thread take-up and feeding mechanism, and auxiliary mechanisms such as thread winding, material pressing, and tooth-dropping.

The base is divided into two forms: platen and chassis. The platen of the table-type machine base plays the role of supporting the machine head and is used as a workbench during sewing operations.

There are many styles of tabletops, such as one-bucket or multi-bucket folding Tibetan type, cabinet type, writing table and so on. The chassis of the chassis-type machine base plays the role of supporting and storing the machine head, making the sewing machine easy to carry and store.

The transmission part of the sewing machine is composed of parts such as a frame, a hand crank or a motor.

The frame is the backbone of the machine, supporting the deck and footrests. When in use, the operator steps on the pedal, drives the rotation of the pulley through the crank, and drives the head to rotate through the belt. Most hand cranks or motors are directly mounted on the nose.

Sewing machine accessories include needles, bobbins, knives, oilers, etc.