Abstract:
An inflatable bathtub which enables efficient use of water and space. The bathtub also provides comfort and ease of use with respect to e.g. cleaning, storing, filling with water, emptying, carrying and moving. The bathtub comprises upright side walls consisting of inflatable side tubes. The side tubes at least partly extend around the circumference of the bathtub in a horizontal plane. The bathtub further comprises a bottom section attached to the bottom side on the side walls. At least a part of the outside of the side walls is curved inwardly in the horizontal plane. The side walls, being up to a certain level flexible, but in a way biased in an inward direction, are forced in an outward direction. The inward bias and the outward pressure by the water results in a straitening of the walls or any other predetermined shape of the side walls.

Description:
TECHNICAL FIELD 
       [0001]    This invention relates to bathtubs and more particularly to an inflatable bathtub that can be conveniently moved from one location to another, and which can be conveniently and quickly inflated, filled with water, drained, deflated and stored. 
       BACKGROUND 
       [0002]    Bathtubs are increasingly becoming popular. A conventional bathtub is made of ceramic or wood materials, fixedly positioned in a bathroom and it generally consumes a lot of space when not in use. In small households or small bathrooms there is often just enough space for a shower, but a fixed bathtub would take up too much space for an efficient use of the bathroom. In addition, installation of a fixed bathtub is complex and relatively expensive. A fixed bathtub needs for example complex plumbing and installation of additional equipment such as drainage. A conventional bathtub is also difficult to assemble and disassemble, and/or remove and requires preferably professional assistance. 
         [0003]    This has led to the development of portable inflatable bathtubs for indoor or outdoor use. Current inflatable bathtubs for indoor use have a rectangular shape. This shape usually makes most efficient use of the limited space in a rectangular shaped bathroom. 
         [0004]    In general a prior art inflatable bathtub comprises a simple construction with side walls comprised of one or more tubular rings which are individually or separately inflatable and form the periphery of the bathtub. Usually an inflatable floor construction is provided, extending between the side walls. Such bathtubs are generally designed with no provision for draining water. Such bathtubs are in most cases only suitable for infants and have not found wide acceptance for adults. 
         [0005]    Various inflatable bathtubs are known in the prior art, some of which will now be described. 
         [0006]    The utility model CN2582517Y by Su Yang describes an inflatable bathtub body provided with an air chamber, and the side face of the bathtub body is provided with an inflation hole and a water discharge opening. The inflation hole is provided with an air plug or an automatic enclosed type air nozzle, and the water discharge opening is provided with a water plug. The air chamber of the bathtub body can be a whole air chamber or a partial air chamber. When the utility model is used, the folded bathtub body is parallelly placed and then is filled with air. After the bathtub body is filled with air, the air plug is used for sealing an air hole and then water is filled. After the utility model is used, the water plug can be taken out for releasing water. 
         [0007]    The utility model CN201350014Y by Tongyu Han describes an inflatable bathtub body wherein an air bag is connected at the right side of the bathtub body; an air outlet pipe and a water drain pipe are respectively arranged at the rear side of the bathtub body; an air outlet valve is arranged on the air outlet pipe; and a water drain valve is arranged on the water drain pipe. 
         [0008]    The utility model CN201267428Y by Weixin Zhou describes an inflatable bathtub comprising four connector links on the inner side wall of the charging bathtub; the connector links are correspondingly arranged on the upper parts of the four corners of the inner side wall of the bathtub. Charging openings on an air cell are respectively provided with a large charging opening and a small charging opening with a large caliber and a small caliber. The bottom of the bathtub is a charging double-layer bottom; a drainage pipe is arranged at the side lower part of the charging bathtub. A filling hole is arranged on a thermal cover. 
         [0009]    These prior art inflatable bathtubs are intended to have a rectangular shape, which enables the most efficient use of an area of a bathroom dedicated for positioning of the inflatable bathtub, in particular when the area is rectangular. These prior art inflatable bathtubs, however, have in common that when they are filled with water the shape tends to expand outwardly under the influence of the mass of the water, resulting in a deformation i.e. bulging of the bathtub. Besides the reduced esthetics, this causes two problems. Firstly, the inflatable bathtub will take more water than needed to reach the desired level of water. Secondly the space around the bathtub will be occupied with the bulging bathtub. 
         [0010]    Accordingly, there is a need for an inflatable bathtub that can address or at least ameliorate the shortcomings associated with prior art bathtubs. 
       DISCLOSURE OF INVENTION 
       [0011]    It is an object of the present invention to provide an inflatable bathtub which enables efficient use of water and space. 
         [0012]    It is a further object of the present invention to provide ease of use of the inflatable bathtub with respect to e.g. cleaning, storing, filling with water, emptying, carrying and moving. 
         [0013]    It is a further object of the present to provide a comfortable bathtub. 
         [0014]    The invention realizes the objectives in the following manner. 
         [0015]    The invented inflatable bathtub comprising one or more upright side walls, the side walls comprising one or more inflatable tubes. The side tubes at least partly extending around the circumference of the bathtub in a horizontal plane. The bathtub further comprises a bottom section attached to the bottom side on the one or more side walls. At least a part of the outside of the one or more side walls is curved inwardly in the horizontal plane. By constructing the outer wall in such a manner that they are curved inwardly, it is taken into account that filling the bathtub with water will exert a force on the side wall in outward direction. The side walls, being up to a certain level flexible, but in a way biased in an inward direction, are forced in an outward direction. The inward bias and the outward pressure by the water results in a straitening of the walls or any other predetermined shape of the side walls. The material of the side walls, the thickness and general sturdiness and stability may be selected based on an expected deformation of the side walls. By choosing the least possible thickness and weight of the material together with a choice for inexpensive the material, a relative light, flexible and inexpensive construction is possible. 
         [0016]    Additional means and measurements are provided to add to the sturdiness and stability of the invented bathtub and to the ease of use and comfort of the bathtub. 
         [0017]    Although the examples given are mostly based on a rectangular bathtub, the design principles and invented construction also apply to other shapes. In particular a popular shape of a bathtub is a round shape. Round shapes encounter the same problems as described in the discussion of the prior art. The invention is easily applicable to different shaped, such as round shaped bathtubs as well. 
         [0018]    To the accomplishment of the above and related objects, this invention may be embodied in the form illustrated in the accompanying drawings, attention being called to the fact, however, that the drawings are illustrative only, and that changes may be made in the specific construction illustrated and described within the scope and spirit of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]    The present invention will become fully appreciated as the same becomes better understood when considered in conjunction with the accompanying drawings, in which equal numbers refer to equal or similar parts. The figures show views of embodiments in accordance with the present invention. 
           [0020]      FIG. 1  shows a perspective view of an inflatable bathtub, according to an exemplary embodiment of the present invention. 
           [0021]      FIG. 2  shows a top view of the inflatable bathtub, illustrated to show inwardly curved sidewalls, according to an exemplary embodiment. 
           [0022]      FIG. 3  shows a side view of the inflatable bathtub, illustrated to show a sloped nature of the inflatable body, according to an exemplary embodiment. 
           [0023]      FIG. 4 a    shows a front view of the inflatable bathtub, according to an exemplary embodiment. 
           [0024]      FIG. 4 b    shows front rear view of the inflatable bathtub, according to an exemplary embodiment. 
           [0025]      FIG. 5  shows a sectional view of the inflatable bathtub comprising a cover with fastening means and optionally opening means according to an exemplary embodiment. 
           [0026]      FIG. 6  shows an adjustable drainage system of the present invention according to an exemplary embodiment. 
       
    
    
     DETAILED DESCRIPTION 
       [0027]    The invention is now described by the following aspects and embodiments, with reference to the figures. Some embodiments of this invention, illustrating all its features, will now be discussed in detail. 
         [0028]    Referring to  FIG. 1 , an inflatable bathtub  10  according to the present invention is shown in its inflated and expanded state, the inflatable bathtub  10  in accordance with an exemplary embodiment of the present invention is preferably made of plastic, rubber, PVC or the like material. The bathtub  10  includes a bathing enclosure  11  to retain water required for bathing of a user  12 . The bathing enclosure Ills defined by multiple surrounding inflatable tubes  13 , 14 , preferably stacked one on the other. Though the embodiment described herein is illustrated to have six such tubes  13 , 14 , it should be understood that the scope of the present invention is not limited to the number of tubes  13 , 14  forming the enclosure  11 . 
         [0029]    The inflation of the inflatable tubes  13 , 14  by injecting air defines opposite sidewalls  13 , and opposite end walls  14  for the bathing enclosure  11 . The inflation of the inflatable tubes  13 , 14  provides an inwardly curved shape to the bathtub  10  of the present invention (see also  FIG. 2 ). According to the present invention, the inwardly curved body makes the bathtub  10  stronger enough to defend the outward force of water retained in the enclosure  11  thereby reducing the risk of expansion beyond the desired periphery which would lead to deformed shapes. 
         [0030]    Referring to  FIG. 2 , the bottom section  20  is preferably covered with a lining comprising one or more layers of watertight covering, preferably but not limited to PVC covering so as to allow easy cleaning of interior of the enclosure  11 . It is equally suited to apply PVC covering to cover all interior walls of the enclosure  11  besides the bottom section  20 . It is found that use of PVC covering closes one or more trenches usually found present in conventional bathtubs  10 . 
         [0031]    Besides this, according to the embodiment, there is also provided a plughole  18  positioned on the bottom section  20  to drain excess water remaining close to the bottom section  20  and below the height of the outlets  16   a,    16   b,  which is normally not drained through the provided outlets  16   a,    16   b.    
         [0032]    Referring to  FIG. 3 , the inflated inflatable tubes  13  of the bathtub  10  are arranged so as to provide it a longitudinally sloped body, which provides more comfort for the user  12  being seated inside for bathing. Further, the slope or inclination towards the lower end helps the retained water to get drained easily. More particular the sloped shape adds to the sturdiness and stability of the bathtub. 
         [0033]    A top inflatable tube  14  out of six defines a support for the bather/user using the bathtub  10 . The support may serve as a back, neck or head support for example. Hereinafter the support is referred to as back support. 
         [0034]    Referring to  FIGS. 4 a   - 4   b,  there are three main air valves  17   a,    17   b,  and  17   c  provided on an end wall  14 . According to the operational features of the present invention, these three air valves  17   a,    17   b,    17   c  are arranged to inflate each of six inflatable tubes  13 , 14  forming the surrounding walls for the bathtub  10 . According to further teachings, each of air valves  17   a,    17   b,    17   c  are unidirectional air valves through which air is injected inside. In the given example each of air valves  17   a,    17   b,    17   c  are meant to inflate a pair of rings  13 , 14 . Also, there is provided an air valve (not shown) for inflation of the bottom section  20  of the bathtub  10 . However, it should be understood that the principle and operation of the present invention is not limited to the number of air valves deployed. The use of unidirectional valves is advantageous as these valves do not allow the bathtub  10  to get deflated when the air inlet port or air valves are left open after inflation. 
         [0035]    According to at least one other embodiment, the air valves  17   a,    17   b,    17   c  may comprise a common connection with a single air inlet port/valve that can be couple to an air pump (e.g. hand or foot operated air pump or electric air pump) so as to allow the user  12  to inflate all of the inflatable tubes  13 ,  14  at once, without the user  12  having to inflate each pair of rings separately, which may be too time consuming. 
         [0036]    Multiple outlets  16   a,b  to drain water out of the enclosure  11  are provided at opposite sides. Multiple outlets may be provided at multiple sides. Each of the outlets  16   a,b  is arranged to receive an adjustable drain system  30  (see  FIG. 6 ). 
         [0037]    Referring to  FIG. 5 , a longitudinally extending bathtub cover  21  is provided with opening means  19 , such as a zipper, that allows accessing the bathing enclosure  11 . The cover may be removably attached to the top of the side walls by a fastening means (not shown). The opening means may be constructed such that the cover may be opened to the edge of the bathtub or to opposite edges of the bathtub, thus allowing a second user to access the bathtub. The cover may add to the stability of the bathtub. 
         [0038]    Referring to  FIG. 6 , the adjustable drain system  30  comprises an assembly  35  comprising a middle connector member  31  with exit part  33  and operable with a handle  32  that helps control the amount of water that can flow out of the interior of the enclosure  11 . Assembly  35  is removably connected to hose  34 . Exit part  33  is insertable into the outlets  16   a  and/or  16   b,  which allows passage to the interior of the enclosure  11 . User  12  can selectively use one of the outlets  16   a,  or  16   b  for attaching the adjustable drain system  30 , while the unused outlets  16   a  or  16   b  can be closed using a stopper (not shown). The facility of multiple outlets  16   a,    16   b  with the user controllable drain system  30  enables the user  12  to strategically use the outlets  16   a,  and  16   b  based on the designated place for draining the water after use. 
         [0039]    The invention and various embodiments and their advantages are summed up below. 
         [0040]    An inflatable bathtub is provided comprising one or more upright side walls, the side walls comprising one or more inflatable tubes, said one or more side tubes at least partly extending around the circumference of the bathtub in a horizontal plane, the bathtub further comprising a bottom section attached to the bottom side on the one or more side walls, wherein at least a part of the outside of the one or more side walls is curved inwardly in the horizontal plane. 
         [0041]    The exemplary embodiments of the invention may comprise the following: 
         [0042]    The side walls may be configured in an at least approximately rectangular configuration. This provides an efficient shape of the bathtub when placed in a more or less rectangular space, such as a bathroom. 
         [0043]    The one or more side tubes may be curved inwardly. 
         [0044]    It is not necessary that the complete area of the upright walls is curved inwardly to provide the desired form. By equipping the bathtubs with one or more inwardly curved side tubes, the areas that are likely to bulge most may be prevented from bulging in the best manner. 
         [0045]    The one or more side tubes may be tapered. 
         [0046]    A tapered shape of one or more side tubes may provide a locally inwardly directed shape. The side tubes may for example be broader at the side where the user&#39;s upper body is normally positioned. This side requires extra sturdiness, because of the heavier and/or broader upper body of the user. If the narrower parts of the side tubes bulge outwardly, this will not influence the general outer shape of the bathtub too much, i.e. the outer wall will straighten instead of bulge. 
         [0047]    The bottom section may be arranged for curving the one or more side walls inwardly. By designing the bottom section like this, the side walls are biased in the inward curved position by default. This supports the inwardly curved shape of the side walls. 
         [0048]    The bottom section may be inflatable. 
         [0049]    By constructing the bottom section as an inflatable part, the bottom section will be more form-retaining and therefore better constructed for biasing the side walls in an inwardly curved position. 
         [0050]    The bottom section may comprise one or more inflatable bottom tubes. 
         [0051]    By means of inflatable tubes, the bottom section itself is constructed to prevent bulging in especially an upward direction. 
         [0052]    The one or more bottom tubes may be curved inwardly in the horizontal plane. 
         [0053]    By curving one or more bottom tubes inwardly the biasing effect is better supported. 
         [0054]    The bathtub may comprise a cover arranged for being attached to the top of the one or more side walls and arranged for covering at least part of the top of the bathtub. 
         [0055]    Current covers may be arranged for multiple purposes:
       keeping the water at the same temperature as much as possible;   providing a rest or a dry place for a user&#39;s hands and/or e.g. a book;       
 
         [0058]    In the embodiment of this invention the cover is in particular also constructed to additionally add to preventing the side wall from bulging. The form of the cover therefore adds to maintaining of the desired shape of the bath. A rectangular cover attached to the top of the walls forces the sidewalls to have a straight or any other desired shape at the places where the cover is attached to the top of the sidewall. 
         [0059]    The cover may be arranged for restraining the one or more side tubes from curving outwardly. 
         [0060]    By attaching the cover to the side tubes the effect is that the side tubes maintain the desired shape. 
         [0061]    The cover may comprise a closure- and opening means, such as a zipper, arranged for providing access to the inflatable bathtub by the user and/or additional users at multiple sides of the inflatable bathtub. 
         [0062]    By adding a closure and opening means, a first user may for example enter the bath tub at a first side while a second user may join the first user at an opposite side. A zipper may be arranged in the cover, extending over substantially the full length of the cover. The zipper may be of the type which has two handles which allow the zipper to be opened and closed from either side. 
         [0063]    The bathtub may comprises one or more back supports positioned on top of the one or more side walls. 
         [0064]    Providing a back support will have the same or a supporting functionality as the cover as described above. The position of the back support is usually at the end of a rectangular bathtub, therefor adding to maintaining of the desired shape of the bath especially at the end. 
         [0065]    The one or more back supports and the cover may be integrated. 
         [0066]    In that case the cover, together with the back support, form a single piece which adds to maintaining of the desired shape of the bathtub along a bigger part of the side walls. 
         [0067]    The one or more back supports may be arranged for restraining the one or more side tubes from curving outwardly. 
         [0068]    The one or more back supports may be removably attachable to the one or more side walls. 
         [0069]    This enables the user to decide whether or not add a back support, or to even add a second back support, for example at the other end of the bathtub for a second user. 
         [0070]    Attachment of the back support and/or the cover to the one or more side walls may be by means of a fastening means of the group comprising:
       a hook and loop fastener, such as Velcro;   a snap fastener;   a zipper.       
 
         [0074]    The one or more side tubes may comprise two or more one-way air valves positioned at opposite sides. 
         [0075]    Positioning of multiple air valves enables a more flexible placement of the bathtub. If one side of the bathtub is close to a wall and difficult to reach from the outside, then the other side may easier to reach. As the invented bathtub is especially suitable for small spaces, placement of the bathtub against a wall may be desirable. Placement to a wall also adds to maintaining a desired shape. 
         [0076]    The bathtub may comprise a lining arranged for covering at least a part of the bottom section and/or a part of the one or more side walls. 
         [0077]    Because of an irregular shape resulting from multiple inflatable tubes, cleaning and draining may be hindered. A lining (e.g. a second skin or extra layer) covering the tubes will straighten the area to be cleaned and may add to more comfort in use of the bath. The lining may for example be of a more comfortable material than the often used PVC. The lining may be treated with antibacterial substance for increased hygiene. The lining may add to maintaining a desired shape as well, especially when constructed of less flexible material than the bottom section itself. 
         [0078]    The bottom section may comprise an outlet arranged for draining of water. 
         [0079]    By adding an outlet to the lowest part possible of the invented bathtub, i.e. the bottom section, the last bit of water is more likely to be drained from the bathtub. This enables easier drying of the bathtub before storage. 
         [0080]    The one or more side walls may comprise an outlet positioned in close proximity of the underside of the bathtub. 
         [0081]    The bathtub may comprise an insertable and removable tap, arranged for regulating the speed and/or amount of drainage. 
         [0082]    Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. 
         [0083]    It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb “to comprise” and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The term “and/or” includes any and all combinations of one or more of the associated listed items. The article “a” or “an” preceding an element does not exclude the presence of a plurality of such elements. The article “the” preceding an element does not exclude the presence of a plurality of such elements. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. 
       INDUSTRIAL APPLICABILITY 
       [0084]    This invention may be used as a temporary or permanent bathtub in a bathroom, a garden or the like. The user may be a grown-up or for example a baby, to be bathed by its parent. After use the bathtub may be stored in a small package, thereby occupying a minimum amount of space when not in use. The technical aspects provide a stable and sturdy construction of the bathtub and easy handling i.e. filling and emptying of the bathtub in an efficient manner.