(under subclass 665) Waterbeds or associated devices in which the surface area of a wall or walls of the structure can increase in size upon a user being positioned on the wall and, upon the user withdrawal, the wall or walls retract to their original size.
(1) Note. The expandable and retractable walls of the bladder may be made from a smooth, homogeneous elastic material, or may be made from a material that has expandable
folds molded therein.
(2) Note. The elasticity of the top, user supporting surface of the bladder may be nonuniform across the top, thereby providing different support characteristics for different users utilizing the waterbed.
