---

Waterbed mattress

Beds utilizing fluid-filled mattresses, commonly referred to as waterbeds, have become quite useful and popular items in recent years. Waterbeds are well known as devices comprising a fluid filled envelope upon which a person may recline with the person comfortably supported thereon as a result of fluid displacement. A waterbed is a mattress-shaped bag filled with water and placed on a bedframe or bunk, for making the surface conform to the user's or the sleeper's body in any position. Waterbeds, or fluid flotation sleeping systems, have become increasingly popular in recent years. A waterbed provides comfortably uniform support and imparts a pleasant fluid effect to the user's body. Waterbed mattresses provide uniform sleeping support and eliminate pressure points on which most of a person's weight rests when reclining on conventional sleeping surfaces. In addition, the co-action of the water and the waterbed mattress produces a floating sensation that enables greater comfort and more restful sleep. A typical waterbed consists of a water filled mattress supported within a rigid frame. Waterbed mattresses contain a large quantity of water which transmits substantial pressure throughout the interior of the mattress when a weight, such as the human body, is on the mattress. Even the weight of the water itself creates substantial pressure in the mattress. Modern day waterbed mattresses are generally equipped with an industry standard flexible filler spout. That spout includes a peripheral rim sealed to the edge of a filler opening through the top wall of a mattress, a generally cylindrical end fitting and a deformable sleeve connected to and extending between the end fitting and rim for enabling the end fitting to be raised above the rim for filling the waterbed mattress and depressed below the rim during use of the filled mattress. Waterbed mattresses contain a large quantity of water which transmits substantial pressure throughout the interior of the mattress when a weight, such as the human body, is on the mattress. Even the weight of the water itself creates substantial pressure in the mattress. When filled with a desired volume of water, the mattresses are inflated so that top walls thereof occur on horizontal planes, spaced above the bottom walls thereof, and that are near or substantially coincidental with the top planes of their related frames, defined by upper edges of the side and end walls thereof.

---