The rotary hook is an essential part of modern-day sewing and embroidery machine designs. It is a spinning hook that encircles the bobbin thread, creating the lock stitch. This type of hook was invented by Allen B. Wilson in 1851 and patented a year later in 1852. It is a fairly standard piece of sewing equipment and is easy to take care of.
This spinning hook is C-shaped with a pointed tip, which continuously rotates in place. It is located in the front, bottom section of the sewing machine and surrounds the bobbin case, which holds and tenses the bobbin thread. The point of the hook catches the thread, which is pushed down through the material by the needle as it spins and loops the thread to make the lock stitch.
Allen B. Wilson invented the rotary hook in 1851. He partnered with Nathaniel Wheeler shortly after breaking from a previous unsatisfactory business partnership. Wheeler was excited to join Wilson's team after learning about his vibrating shuttle machine and early model of the sewing machine. The final design was named the Wheeler and Wilson principle, and a patent was awarded on 15 June 1852.
Nearly all embroidery machines have a rotary hook, and many sewing machines use a rotary hook rather than an oscillating hook. There is a fairly simple way to tell if a sewing machine is using a rotary or an oscillating hook. Bobbins that move in a back and forth motion are oscillating hooks, while rotary hooks spin in a full circle. In a sewing machine, the bobbin carriage and rotating hook are located at the bottom front of the machine, but in an embroidery machine the assembly can be moved to the left side, front, or top of the machine.
When performing a manual feed stitch on an embroidery or sewing machine, a rotary hook is ideal. A manual stitch indicates a disengaged drop feed dog, which is the mechanism that normally moves rapidly up and down, guiding the thread into the material. This is a very customizable type of stitch because its length is controlled by the motion of the material. The rotating hook is perfect for this type of stitch because, unlike other bobbin driver designs, this type of hook holds the bobbin thread at the proper tension.
The rotary hook doesn't require much maintenance. To ensure the best performance and lifetime, a once-weekly cleaning with an oil-based lubricant is recommended. The cleaning repels water, protecting the metal from rust, and removes lint, dirt, and other particles. Proper care for the hook can also reduce thread breakage.