flight clothing, nylon, twills, and lightweight canvas. 111 W 151 Sewing Machine The 111 W 151 sewing machine is also a single- needle, lockstitch, rotary hook machine, intended for high-speed straight stitching of medium heavy materials. The 111 W 151 sewing machine differs from other models of the class 111 machines in that it has a single presser foot instead of the alternating presser foot. 111 W 152 Sewing Machine The 111 W 152 sewing machine is a single- needle, lockstitch, compound feed machine with a vertical axis sewing hook. This machine has alternating pressers with a 3/8-inch lift. It has a safety clutch that prevents the hook from being damaged or getting out of time due to accidental strain. 111 W 153 Sewing Machine The 111 W 153 sewing machine is similar to the 111 W 152, but it is used for sewing heavy work such as automobile and truck upholstery, tents, awnings, and leather flight jackets. 111 W 154 Sewing Machine The 111 W 154 sewing machine is also similar to the 111 W 152, but its alternating pressers have a lift of 1/2 inch, and the machine is designed for stitching upholstery work, leather coats, and binding heavy materials such as felt padding. 111 W 155 Sewing Machine The 111 W 155 sewing machine is similar to the 111 W 154 except that its minimum stitches per inch is 3 1/2, and it has an adjustable lifting eccentric for instantly setting the alternating pressers to the minimum amount of lift required for the work to be sewn. FUNCTIONAL FEATURES The oiling parts for class 111 sewing machine are shown in figure 9-24A. Figure 9-24B identifies 239.448 Figure 9-24B.—Class 111 sewing machine, front view showing components and parts. 9-19