The sewing machine
The normal household sewing machine belongs to the group of lock stitch sewing machines, i.e. the sewing machine works with 2 threads, a top thread, and a bottom thread.
By entangling the two threads creates a uniform stitch pattern that looks the same on both. On the model, the sewing machine can also sew zigzag, pattern and utility stitches.
To sew, you need a sewing needle, gripper, bobbin case, and bobbin, upper and lower thread, as well as feed dog and thread lever. In principle, all sewing machines, in spite of the different makes and makes, are very similar.
Parts of the sewing machine shown above can be found on almost every sewing machine that can sew straight and zigzag stitches (except for stitch patterns and extension table).
The sewing needle
The sewing machine needle has its eye at the top in contrast to the hand needle. It pierces the fabric with the upper thread. When the needle drops, a loop forms. This loop is caught by the hook tip. Whole thing down again (see graphic so a stitch is created.)
The gripper and bobbin case
The function of the gripper is to grasp the upper thread loop with the hook tip, to widen it and to wrap the upper thread around the quiescent bobbin case.
There are different gripper systems. Depending on the model, these may differ from the illustration.
Known systems include, for example, the CB gripper (pictured above), the rotary gripper, the horizontal gripper and the eyeglass gripper.
Upper and lower thread
Upper and lower thread regulate the thread tension, which is one of the most important, if not the most important factor for a clean stitch pattern. More about thread tension here.
The thread lever
The thread lever releases the required amount of needle thread for the loop. After circumnavigating the thread around the bobbin case, the lever pulls the excess thread back up.
The entanglement of the two threads in the fabric is tightened by the threading lever, in cooperation with the forward-moving feed dog, and then immediately fetches the required amount of thread for the next stitch on the best sewing machine reviews.
Function – How to create a stitch
- The needle, with the upper thread, penetrates through the fabric into the bobbin area.
- The upper thread is caught by the gripper. The needle goes up again.
- The gripper pulls the upper thread, which forms a loop, around the bobbin case.
- The thread loop slips down from the hook and lies around the bobbin thread.
- Both threads are tightened upwards. A lock stitch has been created.
The task of the transporter is to transport the fabric to the set stitch length forward or backward. He also presses the fabric layers to firm together while sewing. It is adjusted by the stitch length selector.
The sewing pressure
The sewing pressure is the applied pressure on the fabric. This occurs when it lies under the presser foot/presser foot. He presses the fabric layers together so that they can be transported together evenly.
In addition, the fabric is held tight so that the Stitch pattern is even. By the way, the sewing pressure also regulates that the fabric is not pulled down so that stitches are left out or the needle gets caught.
Interaction of presser foot and feed dog
The fabric is held by the presser foot and needle plate when the needle and thread penetrate. The feed dog goes down as the needle continues to penetrate.
The needle is pulled out of the fabric while the feed dog moves forward. The presser foot continues to press on the fabric.
The needle and feed dog move upwards to create the stitch. The presser foot continues to press the fabric onto the needle plate.
Presser foot and needle plate hold the fabric while the stitch is tightened. Then the feed dog shifts the fabric to the set stitch length.