The sewing machine is among the top most important human inventions. Let me tell you why.
Sewing and embroidery have been in existence for thousands of years. The art of making, mending, and decorating garments is one of the most important human endeavors.
On one side, it gives us high fashion; and on the other, it provides humanity with one of the three basic needs: clothing.
Formerly, all these things were done using the hands. But about 200 years ago, everything changed: the sewing machine was invented.
Have you ever wondered how the machines that keep you clothed work? If you continue reading, you will soon learn how.
The Sewing Machine
The sewing machine is one of those inventions of the industrial revolution that transformed the world. It enabled manufacturers to produce large quantities of high-quality clothing at a low cost.
Consequently, more people were able to access good clothing. Formerly, only the well-to-do could afford high-quality garments.
Like most technological products, sewing machines differ in terms of functionality and performance on the basis of price.
While low-end models are conventional, no-frills electrical designs that one can use at home, high-end sewing machines are sophisticated, electronic machines that you can connect to a computer.
The Sewing Machine’s Loop Stitching System
While, motor vehicles have the internal combustion engine as the center and basis of their functionality, with sewing machine it’s something known as the loop stitching system.
The loop stitch system differs from the sewing technique of ordinary hand stitching. When hand-stitching, you thread a needle whose eye is at the top end rather than close to the sharp point.
After that, you poke the needle through two sides of fabric from one side to the other, and then you poke it back up again. Thus the needle runs in and out of the fabric from side to side until the two pieces of fabric are bound together.
However, it would be complicated and unwieldy for the machine to do this, and so it uses a different technique. It passes the needle only part-way through the fabric.
Also, the eye of the machine’s needle is behind the sharp point rather than at the end like with the hand-sewing needle.
This needle is attached to a needle bar which moves up and down due to the action of the motor by way of a series of gears and cams. As the needle penetrates the fabric, it jerks up a small loop of thread from one side of the fabric to the other.
Under the fabric, a mechanism grabs the loop, wrapping it around another piece of thread or some other loop in the same piece of thread. And that’s how the sewing machine makes a loop stitch.
There are several different types of loop stitches and each has a different way of working, but I won’t get into that right now. The types of loop stitches include chain stitch, which is the simplest, and lock stitch which is sturdier than the former.
The Components of a Sewing Machine
Inside the sewing machine is a series of gears, cams, cranks, and belt, and they all operate due to the action of a single electric motor. How these parts are configured varies for different machines. However, they all operate in a similar way.
The electric motor connects to a drive wheel through a drive belt. On the other hand, the drive wheel rotates the long upper body shaft which connects to various mechanical elements in the machine.
When the end of the shaft turns a crank, it moves the needle bar up and down (and the needle with it). The crank is also responsible for moving the thread-tightening arm.
The tightening arm moves in sync with the needle bar and moves lower to allow enough slack for a loop to form under the fabric. Then it moves up again and tightens the loop after it is released from the shuttle hook.
There is a spool on the top of the machine. Thread is wound around the spool and runs through the tightening arm and through a tension disc assembly.
If you want to tighten the thread feeding into the needle, all you have to do is turn the machine’s disc assembly. Make the tension taut when working on thin fabric and loose on thick fabric.
The first of the mechanical elements found along the shaft is a simple belt whose task is to turn a lower drive shaft. The end of this shaft connects to a set of bevel gears which rotates the shuttle assembly.
By virtue of being connected to the same drive shaft, the needle assembly and the shuttle assembly move in unison.
Also, the lower drive shaft is responsible for moving the linkages that operate the feed dog mechanism. While one linkage moves the feed dog forward and backward at each cycle, another linkage moves it up and down.
The synchronized action of the two linkages ensures that the feed dog presses up against your fabric, pushes it forward, and then moves down to release the fabric.
After this, the feed dog moves backward, and then it presses up against the fabric once again, and the cycle repeats itself on and on.
You control the motor using a foot pedal, enabling you to change the speed of the machine as you see fit. Can you see in your mind now how all these components add up together?
You press against the pedal with your feet, and the motor starts running. Consequently, the running motor kicks of all the processes I have outlined here, and you start sewing.
The motor speeds all these processes at the same rate. So when you press it gently for slow movement, the processes move slower, and so you reduce the pace at which you are sewing – and vice versa. All the processes are perfectly synchronized.
It is fascinating how all these processes and parts work seamlessly together. You can’t see the inner parts; so it always seems like magic when you step on the foot pad, pushing down your foot, and the machine starts humming along.
Now you know it’s no magic – just a mix of different mechanical components connected together to ensure you the best service when sewing!