Lightweight Body Supporting Structure

Abstract

A lightweight body supporting structure having a fluid medium for use as a mattress, bed or the like comprising a flexible, fluid impermeable envelope and a plurality of individual fluid impervious cells disposed within said envelope, each cell containing a gaseous substance or totally void of matter. The envelope is partially filled with a liquid, with the remaining volume being displaced by said individual gaseous filled or void cells. The cells may have flexible or rigid boundaries.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to an improved body supporting device and more specifically to a supporting device having a fluid medium for use as a mattress, bed, pillow or the like. Such a device is commonly referred to as a "water bed" or "water mattress."

The "water bed" has been successfully utilized as a body support because the fluid medium distributes and equalizes the pressure on a supported body, the user finding such a bed extremely comfortable. A body support that equalizes surface pressure is also desirable for hospitalized patients having extremely sensitive or damaged skin tissue.

A major drawback that makes liquid filled beds somewhat impractical is the extremely large volume (and therefore weight) of the water required to fill a supporting container that could accommodate the average sized person without sacrificing those characteristics that make the water bed comfortable. As an example, an 8 foot by 4 foot by 1 foot water filled mattress would weight over 2,000 pounds. Also a puncture or leak in a water bed would literally flood the surrounding area with water, the previous example containing 32 cubic feet of water.

Applicant's invention provides for a body supporting structure having a liquid as the supporting medium, but one in which the entire structure is reduced in weight of the liquid volume with fluid impervious cells containing a gaseous substance or void, without sacrificing the sensation of a completely liquid filled bed.

BRIEF DESCRIPTION OF THE INVENTION

A body supporting structure for use as a bed, mattress or the like comprising a plurality of individual, fluid impervious cells containing a gaseous substance such as air (or partially or totally evacuated) enclosed within a flexible, fluid impermeable shell or envelope, the remainder of the shell volume being filled with a liquid supporting medium such as water. The individual cells may be flexible or rigid and of various shapes and sizes. The shell is shaped to accommodate the intended use either as a bed, mattress, pillow or the like. The proportionate volume of cells to liquid within the envelope is determined so that the sensation of a liquid-filled support is retained; it has been evaluated that a minimum volume of liquid above 20 percent of the envelope volume is necessary.

It is an object of this invention to provide a body supporting structure of reduced weight utilizing a liquid medium.

It is another object of this invention to provide a lightweight water bed.

And yet another object of this invention is to provide a water bed that uses a reduced volume of water.

And yet still another object of this invention is to provide a water bed having a reduced liquid volume without sacrificing the sensation to the body of a completely liquid filled bed.

In accordance with these and other objects which will be apparent hereinafter, the instant invention will now be described with particular reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective, cross-sectional view of Applicant's invention.

FIG. 2 is a vertical cross-sectional view of Applicant's invention.

FIG. 3 is a vertical cross-sectional view of an alternate embodiment of Applicant's invention.

FIG. 4 is a perspective view of the inner cells utilized in an alternate embodiment.

FIG. 5 is a perspective view of tubular cells utilized in an alternate embodiment of Applicant's invention.

PREFERRED EMBODIMENT OF THE INVENTION

Referring now to the drawings, and in particular to FIG. 1, Applicant's body support structure is shown generally at 10 comprising a flexible, fluid impermeable envelope 12 which is partially filled with a suitable liquid 14 (such as water), the remainder of the envelope volume being displaced by a plurality of fluid impervious cells 16 (not all marked for clarity), each cell 16 containing a gaseous substance such as air. The encapsulating surface of each cell 16 may be flexible or rigid, but with sufficient gas pressure inside to prevent collapse from exterior liquid pressure or wall strength to withstand vacuum implosive forces and external liquid pressure. The cells 16 are distributed throughout the envelope in significant numbers to reduce the total weight of the support 10 without reducing the liquid supporting characteristics. The flexible envelope 12 is shaped as a rectangular box similar to a standard mattress. An intake valve 20 provides for the filling of the envelope 12 with liquid 14 and air cells 16 while exhaust valve 18 permits air trapped in envelope 12 to escape during the filling of the envelope, or allows emptying of the envelope 12 of liquid and cells 16. The cells 16 being lighter than the liquid volume being displaced, will tend to collect in the upper portion of the envelope.

FIG. 2 shows support structure 10 with spheroid-shaped cells 16 (in cross-section) within envelope 12, with liquid 14 filling the envelope 12. The inside 30 of cells 16 are filled with a gaseous substance such as air. Each cell 16 displaces a volume of liquid, thereby reducing overall weight of the supporting structure 10.

FIGS. 3 and 4 show an alternate embodiment of Applicant's invention in which the air encapsulating cells are hemispheres 22 fixed to a flat sheet 24. The envelope 12 may contain several layers of sheets 24, again dependent upon the desired weight. The sheet 24 prevents movement of the cells 22 in a lateral direction relative to each other. The sheets are placed inside the envelope during the manufacture of the envelope. Also, the sheets may have hemispheres on each side. The best material for construction of the sheets and hemispheres is polyethylene thin film, which is light weight, flexible but strong.

In FIG. 5, air-filled PVC or polyethylene tubes provide another embodiment for encapsulating air for use inside the envelope 12. The tubes may be wrapped in small bundles by a cord 28, and are inserted during the manufacture of the envelope.

In the preferred embodiment, the spheroid encapuled air cells 16 of FIG. 1 are preferably composed of fluid impervious styrofoam beads, with each bead having hundreds of individual, non-connected, fluid impervious air cells. The beads are small enough to be introduced into the envelope 12 through intake valve 20 whenever the supporting structure is ready for use.

In an alternate embodiment the gaseous filled cells may be replaced by rigid boundary cells that are partially or totally evacuated of all matter, thus placing the cell interior under partial or total vacuum. As long as boundary material is lightweight, the effect would be equivalent to the air filled cells.

The envelope 12 is made from a tough but flexible fluid impermeable plastic film, the thickness being a function of the expected body weights anticipated and the maximum forces expected. In the preferred embodiment a 20 gauge PVC film is utilized. An alternate embodiment could employ a two sided vinyl coated fabric, such as that manufactured under the tradename of "HERCULITE". The envelope is constructed from sheets of film electronically heat sealed together at their perimeters in the desired shape.

The shape of the flexible envelope 12 will depend on the intended use which may include pillow, cushion for hard surfaces, mattress, bed or any support structure that may be used for supporting the body for sleeping, reclining, seating or the like. Although water has been shown as the medium, any suitable, non-solublizing liquid could be used, even one lighter than water for reducing the weight further. In order to prevent the internal cells from excaping during liquid filling or evacuating of the envelope, filters or screens which permit air and liquid flow through are utilized in the intake and exhaust valves.

Thus, Applicant has shown a water bed in which encapsulated gas displaces an equal volume without altering the secondary characteristics of the bed.

The instant invention has been shown and described herein in what is considered to be the most practical and preferred embodiment. It is recognized, however, that departures may be made therefrom within the scope of the invention and that obvious modifications will occur to a person skilled in the art.

Claims

What I claim is:

1. A relatively lightweight structure for supporting various parts of the human body in relative comfort utilizing a liquid supporting medium comprising:

a flexible, fluid impermeable envelope;

a plurality of individual, evacuated, fluid impervious cells contained within said envelope, each of said cells displacing a volume of liquid equal to the volume of said cell;

a liquid supporting medium partially filling said envelope; and

means connecting said cells together to form a unitary structure to prevent relative movement of said cells to each other within a predetermined plane.

2. A supporting structure as in claim 1, wherein said cells include:

a thin film sheet; and

a plurality of thin film herispheres sealed about their perimeters to said thin film sheet,

said hemispheres being imperious to fluid.

3. A supporting structure as in claim 1, wherein:

said cell is an elongated, gaseous filled tube.

4. A supporting structure as in claim 1, wherein:

said cells are flexible, thin film plastic shells encapsulating air.