Bathtub cushion lift assembly
BACKGROUND OF THE INVENTION 
     It is extremely difficult for many people to take unattended baths because of the configuration of a conventional bathtub. Persons such as the handicapped, convalescents, expectant mothers, and the elderly often fine it extremely difficult to utilize conventional bathtubs without assistance and such difficulties are often focused on their inability to lower themselves into the tub, and upon completion of the bath, to lift themselves out of the tub. Not only is the entrance and exit into and out of the tub for such users fraught with considerable difficulties, it is also extremely dangerous due to the ever present possibility of slippage. 
     Bathtub cushion lift assemblies are known in the art such as described in U.S. Pat. No. 3,771,176. In this patent, a cushion lift is described which has an inflatable shell adapted to be positioned on the floor of a bathtub and is connected to the bathtub spout or faucet. Water under pressure is fed through the bathtub spout into the inflatable shell to selectively inflate it to its full elevation wherein its supporting surface is elevated to the approximate height of the bathtub walls to provide a cushionlike support that a person desirous of taking a bath may sit. Once seated on the cushionlike support in the bathtub, the cushion may be deflated whereby the person sitting thereon is gradually lowered to the floor of the bathtub. After the bath is completed, the shell may once again be filled to elevate the user upwardly to the top of the bathtub whereby the user may then exit the tub easily. 
     The prior bathtub cushion lift assemblies have provided apparatus helpful for persons such as elderly persons taking a bath; however, persons who have balance problems have need of more specialized lift assemblies. In particular, persons, such as paraplegics, require a cushion lift assembly which is very stable during inflation and deflation of the cushion lift. It is important to these persons that the lift assembly not tilt, rotate, slide or otherwise shift position during the course of bathing. 
     SUMMARY OF THE INVENTION 
     This invention overcomes the difficulties of prior bathtub cushion lift assemblies in providing a stable cushion lift assembly which utilizes features for preventing or tending to prevent tilting, rotation, sliding or shifting position of the cushion lift assembly during use thereof. 
     In the present invention rigid members are disposed on either the top surface of the cushion or the bottom surface of the cushion or both to minimize undesired movement of the cushion during use. The interior of the cushion may be provided with baffles or the like for dampening water oscillations with the cushion. Furthermore, the cushion may be tiered or formed layers so that the cushion may be inflated or deflated in stages for added stability. Also the cushion may be placed in a rigid chairlike structure having an apparatus on the chair back which cooperates with a side wall of the cushion to guide the cushion during raising or lowering thereof. Furthermore, a foldable valve may be provided for effecting controlled discharge of the water within the cushion. 
     Thus, with the present invention, a stable bathtub cushion lift assembly is provided which maintains its stability during inflation and deflation of the cushion. 
     For a better understanding of the invention, reference may be made to the following descriptions of representative embodiments, taken in conjunction with the figures of the accompanying drawings in which: 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an oblique view of a bathtub containing an inflated cushion lift assembly according to the present invention; 
     FIG. 2 is an oblique view of one embodiment of the cushion lift assembly according to the present invention showing a rigid seat disposed on the top panel of the cushion, a rigid bottom panel and a bottom channel for directing water under the cushion; 
     FIG. 3 is an oblique view of another embodiment of the cushion lift assembly according to the present invention having a removable rigid seat assembly; 
     FIG. 4 is an oblique view of another embodiment of the cushion lift assembly according to the present invention having an inflatable seat assembly; 
     FIG. 5 is an oblique view of another embodiment of the cushion lift assembly according to the present invention including a chairlike frame assembly for cooperating with straps on a wall of the cushion lift assembly to support and guide the cushion as it is inflated and deflated; 
     FIG. 6 is an oblique view of another embodiment of the cushion lift assembly according to the present invention showing a compartmentalized construction; 
     FIG. 7 is a cross sectional view of another embodiment of the cushion lift assembly according to the present invention showing another compartmentalized construction. 
     FIG. 8 is an oblique view of another embodiment of the cushion lift assembly according to the present invention having dampening strips for dampening water oscillations within the cushion; and 
     FIG. 9 is an oblique view of another embodiment of the cushion lift assembly according to the present invention showing a foldable valve assembly for controllably discharging the contents of the inflated cushion. 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     A conventional bathtub 10 is shown in FIG. 1 having a floor 12 and substantially vertical sidewalls 14. Water is introduced into the bathtub through conventional hot and cold valves 16 and a common faucet or spout 18 as shown. It being understood that individual conventional hot and cold faucets could also be used. 
     The cushion lift assembly of the present invention is an improvement for the cushion lift assembly described in U.S. Pat. No. 3,771,176 and includes a selectively shaped inflatable shell 20, having a shell connector 59 which is connected by a standard connector to sleeve valve 22. Sleeve valve 22 is included within filler tubing 24 at one end thereof, the other end of filler tubing 24 is connected to a pressure relief valve 26 and an elastic sleeve 28 and associated sealing means. The sleeve 28 is adapted to snugly fit over the bathtub spout 18 and to be secured thereto in essentially watertight relation. Were the bathtub provided with a corresponding faucet for each of the hot and cold valves 16, the elastic sleeve 28 could be T-shaped so as to connect the hot and cold faucets with filler tubing 24. 
     The shell 20 is suitably formed of highly flexible sheet material of requisite strength and of limited elasticity. Suitable materials include resinous water impervious sheet materials, such as vinyl sheet or the like. Such shell 20 is preferably constituted so as to be of generally rectangular polyhedron shaped when in inflated condition, and of a transverse dimension that will compressively engage the side walls of the bathtub with which it is to be used. 
     Water under pressure for shell inflation is supplied to the cushion lift assembly through the bathtub spout 18. Such water will pass through the elastic sleeve 28, the pressure relief valve 26, the length of filler tube 24 and the sleeve valve 22 into the inflatable shell 20. 
     Any air which is either present in the deflated shell or which is introduced thereinto as a part of the incoming water stream may escape through automatic relief valves 29 in the form of button screens having a bottom layer of foam rubber secured to the bottom thereof. These automatic air relief valves release the air while preventing the discharge of the water from within the shell. 
     The safety or pressure relief valve 26 opens when the pressure of the water within the shell reaches a predetermined level. This prevents a pressure build-up within the shell beyond that level thereby protecting the shell from rupture or other failure due to exercise pressure. 
     The sleeve valve 22 is a conventional valve and is described in U.S. Pat. No. 3,771,176. In operation, a sleeve with holes is rotated to align these holes with corresponding holes in tube 24, to deflate shell 20. Furthermore, the rate of discharge is controllable so that the cushion may be lowered at a rate comfortable for a person seated on such cushion. 
     In operation of the described unit, water from spout 18 is directed through the filler tube 24 to shell 20 to inflate such shell. The shell will continue to inflate until it reaches a fully inflated condition and the pressure therewithin builds up to a magnitude equal to the pressure at which the pressure release mechanism will become operable. At this point, the side walls of the shell 20 will compressively engage the walls of the bathtub and the upper surface thereof will be at a height substantially equal to the height of the bathtub walls. A person sits on the side of the bathtub, slides over onto the upper surface of the cushion, swivels his legs over the side of the bathtub, and opens the sleeve valve 22 allowing the water to be discharged from the cushion whereupon the shell will become deflated at a slow rate, thus lowering the person gradually to the floor of the bathtub. 
     When the person desires to get out of the bathtub, the sleeve valve 22 is closed, the faucet fitting 28 is replaced in position if it has been removed and the water is turned on causing the shell to again become inflated, and to effect a selectively directed elevation of the person up to the top of the side walls of the bathtub. The person then swivels his legs over a side of the bathtub onto the floor and stands up. 
     Persons suffering from balance problems such as paraplegics require bathtub cushion lift assemblies which are stable and will not tilt, rotate, slide or otherwise shift position during the course of bathing. 
     One embodiment of the present invention directed to this end is shown in FIG. 2. The shell 20 includes a floor bottom panel 21 constructed of rigid material. This structure tends to stabilize the shell 20 when inflated and tends to prevent undesired rotation of the shell 20 when the cushion lift assembly is being used. 
     The bottom panel 21 may be provided with a channel 23 as shown in FIG. 2 passing from the front of the shell 20 to the rear thereof which would permit water otherwise trapped between the rear wall of shell 20 and the rear wall of the bathtub, designated 100 in FIG. 1, to flow to the bathtub drain. 
     FIG. 2 also shows another embodiment of the present invention having a selectively shaped seat 31 disposed on the top panel 30 of the shell 20. The seat 31 may be constructed of rigid material and may be integral with or attached to the top panel 30 of the shell 20 by bonding such as with an adhesive or by snaps, Velcro strips or other such means (not shown). 
     FIG. 3 shows another construction of a shell 20 having a seat. Here the top panel 30 of shell 20 is provided with an envelope 32 into which a substantially rigid seat panel 34 may be inserted. The mouth 33 of the envelope 32 may be provided with a plastic zipper, snaps, Velcro tape, or other suitable means (not shown) for closing the envelope to retain the panel 34 therein and to prevent dirt from entering the envelope. 
     The seat constructions as described and shown in FIGS. 2 and 3 aid in stabilizing the top panel 30 of the shell 20 as it inflates and deflates, and also prevents the crumpling of and other displacement of the top panel 30 when there is little or no water in the shell 20. 
     Another type of seat construction is shown in FIG. 4, where the seat comprises an air inflatable cushion 36 which may be separately attached to or formed on the top panel 30 of shell 20. The cushion is fashioned, for example, in a generally toroidal shape thereby forming a continuous ringlike ridge on the top panel 30 and is provided with a nozzle 38 for inflating the cushion 36. Alternately, the cushion 36 could be inflated by the air in shell 20 which would otherwise escape through relief valves 29 as shown in FIG. 1 when the shell 20 is filled with water. The cushion 36, when inflated, is designed to minimize sliding by the user when sitting on the cushion either when the shell 20 is inflated or when the shell 20 is virtually deflated. It should of course be realized that although the cushion 36, as shown in FIG. 4, is toroidal, various other shapes would also be effective. Furthermore, the cushion 36 could be inflated with other fluids, or the cushion 36 could be non-inflatable and be fashioned of foam, rubber, or the like. 
     FIG. 5 displays a rigid frame assembly 40 which may be foldable or collapsible and may be fashioned of plastic or aluminum tubing or the like for guiding the shell 20 during inflation and deflation thereof. The frame assembly 40 includes a vertically extending &#34;U&#34; shaped back frame portion 41 with the open ends connecting to open ends of a horizontally extending &#34;U&#34; shaped base frame portion 42. Extending between the arms of the &#34;U&#34; shaped base frame portion 42 is a flexible supporting material 43 such as plastic webbing. 
     A tubular guide 44 concentrically surrounds each of tubular arms of the &#34;U&#34; shaped back frame portion 41. A cross member 45 is attached to and extends between the tubular guides 44. The tubular guides 44 are sized to slidably move on the tubular arms of back frame portion 41. 
     In a preferred embodiment, the shell 20 is provided with straps 46 which extend around the cross member 45 as shown in FIG. 5; however, other means could be used to attach the shell 20 to cross member 45 and are intended to be within the scope of this invention. 
     In use, the frame assembly 40 is positioned in the bathtub with the base frame portion 42 positioned on the floor of the bathtub and under the bottom panel of the shell 20. As the shell 20 is filled with water and inflates, the straps 46 will carry the cross member 45 upwardly. The tubular guides 44 cooperating with the arms of the back frame portion 41 guide the shell 20 during inflation to reduce rolling, pitching or tilting which may otherwise occur during inflation. As the shell 20 is deflated, this structure also acts to increase the stability of the shell 20 for a user seated thereon. 
     In addition, the back frame portion 41 provides support for a bather when the shell 20 is deflated and permits a person to sit comfortably in the bathtub with a back support. 
     As shown in FIG. 6, the shell 20 may be provided with interior valves or panels 48 attached to the interior surfaces of the peripheral walls of the shell such that when the shell 20 is fully inflated, the interior panels 48 are generally parallel with the top panel 30 and the bottom panel, thereby dividing the shell 20 into horizontally tiered compartments. Each of the interior walls 48 is provided with a plurality of holes or apertures 50 to provide fluid communication between adjacent compartments. With this construction, the shell 20 may be inflated or deflated in stages thereby providing a more firm, secure support for the user. Furthermore, the interior panels 48 may be fashioned of substantially rigid material, thereby providing additional stability of the shell 20. 
     Another construction of a horizontally compartmentalized shell 20 is shown in FIG. 7. In this embodiment, the shell 20 includes a series of inflatable, toroidal shaped tubes 52. In the embodiment, as shown, the tubes 52 are sized to provide a generally frusto-conical overall shape for shell 20. A plurality of holes (not shown) are provided between adjacent tubes in the regions of their interfacial engagement to permit fluid communication between the interiors of adjacent tubes. This construction also permits the shell 20 to be filled in stages. Also, the uppermost tube could be constructed similar to the seat cushion 36 shown in FIG. 4 and described above to provide a ring shaped seat when the other tubes of the shell 20 are inflated or deflated. Furthermore, the tubes 52, as shown in FIG. 7, were shown as being toroidal for purposes of illustration only. The shape is not critical and it is intended that other shapes such as a square shape may be utilized. 
     As shown in FIG. 8, the shell 20 may be provided with dampening members 54. It has been found that when these members 54 are disposed within the shell 20, water oscillations within the shell 20 are reduced thereby increasing the stability of the overall structure. The dampening members 54 are attached to opposing interior walls of shell 20 in the embodiment shown in FIG. 8. The three dampening members 54, shown in FIG. 8, have a circular, rectangular and triangular cross-sectional shape; however, other shapes and configurations are all intended to be within the scope of this invention. 
     In a preferred embodiment, the dampening strips 54 are hollow and are constructed of flexible material. Holes 55 provide fluid communication between the interior of shell 20 and the interior of dampening member 54, such that when the shell 20 is inflated, the dampening members 59 are also inflated. With this arrangement, the shell 20 and dampening members 59 may be deflated together to facilitate transportion and storage of the bathtub lift cushion. 
     Another embodiment is shown in FIG. 9. In this embodiment, a foldable valve 56 is used to control the discharge of water from the inflated shell 20, and as shown here, may eliminate the need for the sleeve valve 22 as shown in FIG. 1. 
     The foldable valve comprises a foldable, elongate sleeve member 58 having a body portion 60 having one terminal end thereof in fluid communication with the shell 20 through a portion of the filler tube 24, or alternatively through a direct connection with shell 20. The other terminal end 62 of sleeve member 58 is open. A non-buoyant weight or closure means 64 is secured to the sleeve member 58 near the open terminal end 62 such that when the sleeve member 58 is in an unfolded position, the weight 64 lies below the sleeve member 58 adjacent the floor of the bathtub, as shown by the dotted lines of FIG. 9. A float member 66 is attached to the weight 64 by means of a cord or string 68. The float member 66 floats on the surface of the water in the bathtub and enables a person with limited maneuverability to control the foldable valve 58. 
     In operation, the foldable valve 58 is closed by folding the open terminal end portion 62 of the sleeve member 58 back upon the body portion 60 thereof, with the weight 64 resting upon the two folded over sleeve portions, thereby compressing the walls of the body portion 60 together and forming a fold line 70. The fold line closes the valve 50. With the valve 50 closed, the shell 20 may be inflated. To open the foldable valve 58, the weight 64 is lifted, for example, by maneuvering the float member 66, and moved to the position denoted by the dotted lines of FIG. 9 such that the weight 64 no longer lies on the body portion 60. In this position, the foldable valve is open and the shell 20 may be deflated. With the shell 20 deflated, the user may bathe in the water filled tub, with the float member 66 floating on the water surface. Upon finishing bathing, the user simply maneuvers the float member 66 to again close the foldable valve 50 the shell 20 may then be inflated with water. 
     A cover may be filled over the top portion of shell 20 when in use and removed after use so that the bathtub lift cushion may be left in the inflated condition between uses. The user takes the cover with him and the next user places a new cover over the shell 20. In this manner, the bathtub lift cushion may be kept in a hygenic condition and without the need of deflating the assembly after each bath. The cover may be attached to the shell 20 by snaps, Velcro strips, adhesives or the like and may be disposable. 
     Although particular embodiments of the present invention have been described and illustrated herein, it should be recognized that modifications and variations may readily occur to those skilled in the art and that such modifications and variations may be made without departing from the spirit and scope of my invention. Accordingly, all such modifications and variations are included in the scope of the invention as defined by the following claims: