Sewing machines date back to 1830 when Barthelemy Thimonnier patented the first practical sewing machine. However, the first double-thread sewing machine, which is far more similar to today's sewing machines and would have featured a version of the hook race used today, came from inventor Walter Hunt in 1834. Later contributions from Elias Howe and Isaac M. Singer made the sewing machine a practical alternative to hand sewing.
The hook race is a circular groove that runs around the bobbin case. This groove or track allows the hook to travel in a circular path around the bobbin when the machine is in operation. To access the hook race on a machine you will need to remove the bobbin case. Depending on the brand and model of the sewing machine you may need to move a latch to remove the hook as well.
Each time the needle on a sewing machine stitches into a piece of fabric, a small loop is formed behind the needle. The hook comes down, picks up that loop and wraps the thread around the bobbin. The hook race provides a guided pathway in which the hook travels, allowing it to take up the extra thread and wrap it around the bobbin with each stitch.
A hook race is often the dirtiest part of a sewing machine and requires regular maintenance. Use a small tool such as a watercolor brush or toothpick to clean out the lint that builds up there. After the lint has been removed from the groove, place sewing machine oil on a cotton swap and clean larger pieces of matted lint from this area of the machine. You may require more than one cotton swab to clean this area. For sewing machines that are used daily, the hook race should be oiled each day.
Lint build up is a common problem in hook races. Regular cleaning and oiling will help to prevent problems. A broken needle can easily become lodged in the narrow hook-race groove. If this happens, remove the bobbin case and hook, then gently brush out the broken needle. To prevent a broken needle from becoming lodged in the hook race or other parts, remove all pieces of the needle immediately.