Frameless safety water bed

Abstract

Plastic sheets bonded together define a main water compartment, a bounding air pressure compartment, and a receptacle extending beneath both such compartments to retain any inadvertently leaking water.

Parent Case Text

This application is a continuation-in-part of Ser. No. 221,589 filed Jan. 28, 1972 and entitled "Frameless Water Bed", now U.S. Pat. No. 3,787,907.

Description

BACKGROUND OF THE INVENTION

This invention relates generally to water beds, and more particularly concerns unusual simplifications and improvements in the construction of such beds.

Water bed systems normally incorporate a flexible hollow enclosure or bladder to receive liquid such as water, together with a relatively rigid frame (constructed of material such as wood or plastic) bounding and often supporting the bladder. Such a frame has been felt necessary in order to confine the bladder against spreading under pressure exerted by the weight of a reclining sleeper, in order to maintain a sufficient layer of water in the bladder and beneath the sleeper. While efforts have been made to eliminate need for the rigid frame, in order to reduce cost, none of such efforts have to my knowledge resulted in the unusually advantageous combinations and sub-combinations of elements, mode of operation and results afforded by the present invention, as will appear. The latter include extremely low cost and light weight construction characterized by simplicity, durability, portability, and safety as respects retention of any inadvertently leaking water.

SUMMARY OF THE INVENTION

It is a major object of the invention to provide a water bed construction eliminating need for a rigid frame, while at the same time avoiding water confinement and bladder deformation problems that normally arise in the absence of such a frame, and also avoiding inadvertent water leakage problems.

Basically, the improved water bed comprises plastic sheet structure defining a main water compartment bounded by an pressure compartment; and a safety sheet attached to the sheet structure and extending in underlying relation to both compartments in such manner as to receive and retain any water leakage from the water compartment. As will appear, the safety sheet may consist of flexible plastic material, and it may advantageously be peripherally bonded to the sheet structure along a locus bounding the main extent of the air compartment and at an elevation generally above the bottom level of the water compartment.

These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following description and drawings, in which:

DRAWING DESCRIPTION

FIG. 1 is a perspective showing of a water bed;

FIG. 2 is an enlarged section taken on lines 2--2 of FIG. 1;

FIG. 3 is an enlarged plan view taken on lines 3--3 of FIG. 1;

FIG. 4 is a section taken in elevation prior to inflation of the bed;

FIG. 5 is a plan view of an unfolded "corner" portion of the bed tube;

FIG. 6 is a perspective view of the FIG. 5 "corner," partially folded;

FIG. 7 is a plan view like FIG. 5 showing the same corner portion after nearly completed folding; and

FIG. 8 is an enlarged section taken through a fill valve.

DETAILED DESCRIPTION

Referring to FIGS. 1 and 2, the bed 10 in general includes primary plastic sheeting, as for example is indicated at 11 defining a tube extending in a loop, which may be rectangular as shown; however, other loop shapes are possible. The bed also includes auxiliary upper and lower sheets 12 and 13 extending across the interior space bounded by the loop and overlapping opposed extents of the tube. For example, portion 12a of uppwer sheet 12 overlaps tubular loop extent 11a', and portion 13a of lower sheet 13 overlaps tubular loop extent 11a". In similar manner, where the loop is rectangular, portions 12b, 12c and 12d of the upper sheet 12 overlap loop leg extents 12b', 12c' and 12d', respectively, and portions 13b, 13c and 13d of the lower sheet overlap loop leg extents 12b", and 12c" and 12d". Such overlapping is convexly curved, as shown, to retain or hold the legs against outward deflection in response to water pressure exertion.

The auxiliary sheets 12 and 13 are seen in FIG. 2 to be carried by the tube 11 and to form therewith a closed, interior space or hollow 14 which receives water 15 and is bounded by the tube. After inflation of the tube, but prior to water filling into that hollow, the upper sheet may hang downwardly as indicated by the broken lines 12f.

The tube may with unusual advantage be defined or formed by four elongated flat plastic sheets 11e, the ends of which are V-notched as at 18 in FIG. 5, to form corners, as will now be described. Two such sheets are superimposed and heat sealed along a V-shaped band to form the end interconnection 19 as shown. Next, the extremeties 20 of the interconnection are brought together as indicated by the arrows 21 in FIG. 6, FIG. 7 showing near completion of this step to develop medial folding 22 along the sheet lengths. Upon completion of such inwardly oriented fold development, the two sheets 11 extend at right angles from the corner diagonal seal connection 19, and it will be seen that the four sheets 11e thereby are caused to develop four corners.

Subsequently, the previously referred to upper and lower plastic sheets 12 and 13 are applied in the flat overlay as seen in FIG. 4, and heat sealing is effected along rectangularly extending outer band 24 joining all the sheets. Also, upper and lower heat seal bands 25 and 26 are formed as shown, band 25 being generally rectangular and spaced inwardly of seal 24 and joining sheet 12 to upper extent 11a" of sheet 11e, and band 26 also being generally rectangular and joining sheet 13 to the lower extent 11a" of sheet 11e. Such bands may be curved at the corners as indicated at 24a, 25a and 26a, and excess outwardly lying sheet material may be stripped off about band 24, as is clear from FIG. 3. Accordingly, such heat sealing and stripping may be quickly effected, in FIG. 4 sheet condition.

Expansion of the tube may be accomplished by introduction of air (as from a vacuum sweeper discharge) via a flapper valve unit 30 assembled on the tube, and a similar valve 31 may be employed on sheet 12 to facilitate water introduction into and entrapment within the enclosed space 14. The valve 31 is shown in detail in FIG. 8 as including a cup shaped body 32 having a top flange 33 to which sheet 12 is bonded. The body includes a flap 34 adapted to be downwardly deflected to position 34a when water is introduced, and to seat upwardly in closed position as shown in full lines. An attached cap 35 forcibly fits downwardly into the body, with lip interference at 36, to provide additional sealing. The cap may be elevated to position 35a, as shown.

An important feature of the invention concerns the provision of a safety sheet attached to the plastic sheet structure (which forms the main water compartment 14 and the bounding air pressure compartment 40), the safety sheet extending in closely underlying relation to the air and water compartments to receive and retain any inadvertent water leakage from the water compartment.

In the illustrated example of FIGS. 1, 2 and 4, the safety sheet 41 consists of flexible plastic material, as for example vinyl, and is peripherally bonded to the sheet structure that forms the air and water compartments and along a locus bounding the main extent of the air compartment and at an elevation generally above the bottom level of the water compartment. Thus, for example, safety sheet 41 may be peripherally bonded at seam 24 to all the sheets 11a', 11a", 12a and 13a. As a result, the safety sheet has approximately the same extent as auxiliary sheet 13, and lies directly under the latter, to catch and retain any water leakage. If desired, sheet 41 may also be heat bonded at 26 to sheet 13, for extra safety, i.e., directly below the lowermost extent of the air compartment and along the length of the latter.

All sheets may consist of vinyl plastic material.

Claims

We claim:

1. In a water bed, the combination comprising

a. plastic sheet structure defining a main water compartment and an air pressure compartment extending in a generally horizontal loop bounding the water compartment, and

b. an additional and separate safety sheet attached to said sheet structure and extending in closely underlying relation to the air and water compartments to receive and retain any water leakage from the water compartment,

c. the safety sheet being peripherally bonded to the sheet structure along a locus bounding the main extent of the air compartment and at an elevation generally above the bottom level of the water compartment.

2. The combination of claim 1 wherein the safety sheet consists of flexible plastic material.

3. The combination of claim 1 wherein the sheet structure includes

c. primary plastic sheeting defining a tube forming said air compartment, and

d. auxiliary upper and lower plastic sheets extending across the water compartment, the auxiliary upper sheet overlying the tube and bonded thereto and therealong, and the auxiliary lower sheet underlying the tube and bonded thereto and therealong, the safety sheet directly underlying substantially the full extent of the auxiliary lower sheet.

4. The combination of claim 3 wherein the safety sheet is also bonded to the auxiliary lower sheet directly beneath the lowermost extent of the compartment, and along a loop-shaped locus lengthwise of said air compartment.