Cap.

Patent for a new and improved cap. This design calls for "an adjustable pillow, which can be used when desired, and folded up out of the way when not in use. To accomplish this . . . the cap [has] an air-tight sack or pillow, which can be inflated when needed, and when not in use the air can be withdrawn and the pillow folded up out of the way in the top of the cap" (lines 25-32)