A sewing machine creates a stitch by interlocking two threads: one from a needle and one from a bobbin.
Here’s a breakdown of the process:
- Needle Thread Insertion: The sewing machine needle, carrying the needle thread, pierces the fabric.
- Looper/Hook Engagement: A rotating hook or looper catches the needle thread as it passes below the fabric.
- Bobbin Thread Interlocking: The hook/looper carries the needle thread around a bobbin, which holds a second thread called the bobbin thread. This interlocks the two threads.
- Stitch Tightening and Fabric Advancement: The take-up lever pulls the needle thread back up, tightening the stitch and pulling the bobbin thread up underneath the fabric. Simultaneously, the feed dogs pull the fabric forward, ready for the next stitch. According to the provided reference, this cycle repeats for every stitch, relying on precise timing.
| Component | Function |
|---|---|
| Needle | Carries the top thread through the fabric. |
| Bobbin | Holds the bottom thread that interlocks with the top thread. |
| Hook/Looper | Catches the needle thread and loops it around the bobbin. |
| Feed Dogs | Advances the fabric after each stitch. |
| Take-up Lever | Tightens the stitch. |
The coordinated movement of these components creates a consistent and secure seam.
