Abstract:
A sleep surface is formed by joining longitudinal sides of two juxtaposed air bladders, thereby providing a continuous sleep surface having two independently inflatable air chambers. The union of the two bladders ensures that the bladders remain in a desired position despite being repeated inflated, deflated, folded and unfolded.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     Airbeds are rapidly gaining popularity as an alternative to inner spring mattresses. One of the most attractive features of an airbed is the inherent firmness adjustability. As opposed to a non-adjustable inner spring mattress, the firmness of an air bed can be quickly adjusted simply by changing the air pressure in the bladders of the bed. The larger beds include two juxtaposed bladders, thereby providing two independently adjustable sleep surfaces in a single bed.  
         [0002]     Originally, beds offering two bladders were constructed simply by providing a cover, inserting foam borders around the inner sidewalls of the cover to provide a desirable shape for the mattress, and inserting two independent juxtaposed bladders inside the foam borders. Some customers expressed concern that when they were on inside edge of their bladder, toward the center of the bed, their body weight forced all of the air in the bladder toward the outer side of the bladder, leaving them in a low point on the mattress. If their sleeping partner was laying on the center of the other bladder, the inside edge of the spouse&#39;s bladder would be fully inflated. The discontinuity between the inside edge of the compressed bladder and the fully inflated adjoining edge of the adjacent bladder, created an uncomfortable sleeping surface. Though this problem was somewhat alleviated by the incorporation of foam covers and pillow top mattress covers, the effect was still noticeable.  
         [0003]     Recently, another advantage of airbeds has resulted in the development of sleeper sofas with airbed mattresses. The advantage is that the airbeds can be deflated, virtually eliminating the space used by the mattress. Conventional sleeper sofa designs are plagued with a struggle between providing a comfortable sleep surface when the bed is deployed, and providing an attractive sofa when the bed is hidden away. A thick, comfortable mattress is difficult to fold into a couch. Mattresses that are foldable are too thin to insulate a sleeper from the non-uniform support surface under the mattress.  
         [0004]     Airbed mattresses eliminate this problem because they can be deflated before the bed is folded into the couch. Thus, the thickness of the mattress is completely independent of the mechanical structure of the sofa mechanisms. The development of airbed sleeper sofas has quickly progressed to the inclusion of a mattress having two bladders.  
         [0005]     A sleeper sofa airbed mattress with two bladders brings with it the same potential problem of a gap between the mattresses when inflated. The deflation of the bladders during storage creates a new potential problem as well. Namely, the deflated bladders may become overlapped or otherwise wrongly positioned during the folding and unfolding of the sleeper sofa. Placing a foam border between the bladders is not effective because the foam border itself is likely to become displaced when the bladders are deflated.  
         [0006]     Thus, there is a need for an airbed mattress having two independent bladders that remain in position while being inflated, deflated, folded and unfolded. There is a further need for this mattress to provide a minimum level of firmness across the extents of the mattress so a sleeper does not feel drawn to a depression in the middle of the bed.  
       BRIEF SUMMARY OF THE INVENTION  
       [0007]     The present invention relates to an airbed mattress that provides a solution to the aforementioned problems. More specifically, the present invention relates to an airbed mattress that includes two juxtaposed mattresses that are joined along adjoining longitudinal edges. The union formed not only keeps the bladders in place during deflation and folding, a bridge is formed between the mattresses creating a relatively constant sleep surface across the extents of the mattress.  
         [0008]     Thus, one aspect of the present invention provides a sleep surface for two people comprising a first bladder having a longitudinal side and a second bladder having a longitudinal side attached to the longitudinal side of the first bladder. Each bladder is constructed and arranged to maintain an air pressure therein that is independent of an air pressure in the other bladder. The feature of two independently adjustable sleep surfaces is thus maintained.  
         [0009]     The longitudinal sides of the two bladders may be heat welded, zipped, connected with hook and loop fasteners, snap fasteners, tied, or any acceptable fastening means. Additionally, the sides of the two bladders may be connected at an upper edge or both and upper and lower edge.  
         [0010]     Another aspect of the present invention provides a method of creating an uninterrupted sleep surface with two bladders. The method includes providing a first elongate bladder and a second elongate bladder. The bladders are then juxtaposed and joined. Joining the bladders is accomplished through heat welding, zipping, connecting with hook and loop fasteners, connecting with snap fasteners, tying the bladders together, or any acceptable fastening means. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a perspective view of sections of two bladders to be joined to form the sleep surface of the present invention;  
         [0012]      FIG. 2  is a perspective view of a joined portion of a preferred embodiment of the sleep surface of the present invention; and,  
         [0013]      FIG. 3  is a perspective view of a joined portion of an alternative embodiment of the sleep surface of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0014]     Referring now to  FIG. 1 , there is shown a pair of air bladders  12  and  14  that are to be joined to form an air mattress  10  of the present invention. The air mattress  10  is designed to accommodate one person on each bladder  12  and  14 . Both of the air bladders  12  and  14  have upper surfaces  16 , lower surfaces  18  and longitudinal sides. The longitudinal side  20  of the first air bladder  12  is includes an upper lip  22  and a lower lip  24 . Similarly, the longitudinal side  21  of the second bladder  14  includes an upper lip  26  and a lower lip  28 .  
         [0015]     Referring now to  FIG. 2 , the air mattress  10  of the present invention has been formed by joining the longitudinal side  20  of the first air bladder  12  to the longitudinal side  21  of the second bladder  14 . In a preferred embodiment of the present invention, the upper surface  16  of the first air bladder  12  may be made continuous with the upper surface  16  of the second air bladder  14  by permanently attaching the upper lip  22  of the first longitudinal side  20  to the upper lip  26  of the second longitudinal side  21 . In this manner a permanent union  30  is created between the first longitudinal side  20  of the first air bladder  12  and the longitudinal side  21  of the second air bladder  14 . One skilled in the art will realize that, the term “continuous”, as used herein, is referring to the somewhat planar and horizontal upper surface of the resulting mattress  10 . This may be accomplished by joining a portion or all of the upper lip  22  of the first longitudinal side  20  to the upper lip  26  of the second longitudinal side  21 . Additional, this union may be intermittent.  
         [0016]     More preferably, the strength and integrity of the union  30  may be increased by making the lower surface  18  of the first air bladder  12  continuous with the lower surface  18  of the second air bladder  14 . This continuity may be achieved by permanently attaching the lower lip  24  of the first longitudinal side  20  to the lower lip  28  of the second longitudinal side  21 . The permanent union  30  may be achieved through any acceptable joining mechanisms or techniques including, but not limited to, heat welding, adhering, bonding, or sewing.  
         [0017]     More specifically, the union  30  of the embodiment shown in  FIG. 2  has been formed by overlapping the upper lips  22  and  26 , overlapping the lower lips  24  and  28 , and joining the contacting surfaces together. The resulting union  30  is further strengthened, in a preferred embodiment, by adding reinforcement members  32  over the joined lips on the upper and lower surfaces  16  and  18 , and joining these members to both bladders  12  and  14 .  
         [0018]     Reputable airbed manufacturers warranty the bladders sold against leaks. In the event of a leak in one of the bladders  12  or  14 , the manufacturer will send a replacement bladder in exchange for the faulty bladder. If the airbed includes a mattress  10  that includes two bladders  12  and  14  that are permanently joined, the exchange will necessarily include the shipment of a non-defective bladder along with the defective bladder. In order to minimize the additional shipping charges as well as the costs associated with accepting a perfectly functional bladder as defective, a preferred embodiment of the mattress  10  is shown in  FIG. 3  that includes a separable union  32  that may be disassembled in the event that it is desired to separate the bladders  12  and  14 , such as for purposes of exchanging a defective bladder.  
         [0019]     The separable union  32  is effected by a joining mechanism  34 . The joining mechanism  34  is shown as a zipper but one skilled in the art will quickly realize that other joining mechanisms may be utilized without departing from the scope of the invention; for example, hook and loop fasteners, adhesives, snaps, laces, buttons, magnets, or the like may be used. Also, the union  32  may be continuous, intermittent, or partial. Preferably, a first portion  36  of the joining mechanism  34  is attached to the upper lip  22  of the first bladder  12 . A second portion  38  of the joining mechanism  34  is attached to the upper lip  26  of the second bladder  14 . The first portion  36  and the second portion  38  are configured to mate with each other in order to form separable union  32 .  
         [0020]     Preferably, the separable union  32  further includes a second joining mechanism  40 , which may or may not be similar to joining mechanism  34 . The joining mechanism  40  includes a first portion  42  attached to the lower lip  24  of the first bladder  12  and a second portion  44  attached to the lower lip  28  of the second bladder  14 . The first and second portions  42  and  44  are configured to mate with each other to join the lower lips  24  and  28  together.  
         [0021]     Heretofore, the unions, either permanent or separable, have been described as being formed along either the top edges of the adjacent bladders  12  and  14 , or the top and bottom edges of bladders  12  and  14 . Some of the objects of the present invention may be accomplished by adjoining the bladders  12  and  14  along a mid portion of their adjacent side walls. However, doing so not only lowers the effective “bridge” that is formed between the two bladders  12  and  14 , it necessarily increases the separation force felt by the union when a person is laying on or near the union. Therefore, while such a union is contemplated and considered within the scope of this disclosure, the union would have to be of heavier construction to withstand the additional force. Thus, the preferred union, either permanent or separable, is one where the top edges are joined.  
         [0022]     In operation, a sleep surface having a continuous upper surface  16  by juxtaposing the first bladder  12  and the second bladder  14 . Once juxtaposed, a union  30  or  32  is formed by attaching the upper lip  22  of the first bladder  12  to the upper lip  26  of the second bladder  14 . Preferably, the union may be made stronger by attaching the lower lip  24  of the first bladder  12  to the lower lip  28  of the second bladder  14 .  
         [0023]     Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes thereof. In that the foregoing description of the present invention discloses only exemplary embodiments thereof, it is to be understood that other variations are contemplated as being within the scope of the present invention.  
         [0024]     Accordingly, the present invention is not limited in the particular embodiments which have been described in detail therein. Rather, reference should be made to the appended claims as indicative of the scope and content of the present invention.