Machines 31-17, 31-18 and 31-21 have one needle and an oscillating shuttle and are designed for stitching shoes and other articles of leather. They are equipped with knee lifters and roller pressers and have oil cups for Tubricating the thread. Machines 31-17 and 31-21 have a drop feed and Machine 31-18 has a wheel feed. These machines have a clear space of 10.25 inches at the right of the needle.