Abstract:
A method and apparatus for coupling and decoupling an air supply hose to an inflatable device. The inflatable device may be adapted to support a patient, such as an air mattress or an inflatable patient transfer mat that rides on an air cushion. The method and apparatus utilize an air inlet that normally assumes a flat orientation. The air inlet includes resilient members that allow the air inlet to flex out of the flat orientation in response to a compressive force. The compressive force changes the air inlet&#39;s orientation into a generally round orientation that is sized to accept an air supply hose. A collar on the air supply hose is able to frictionally engage an edge in the air inlet in order to prevent undesired removal of the hose from the inlet. Magnets may be used to help return the inlet to the flat orientation when not in use.

Description:
[0001]    This application claims priority to U.S. provisional application Ser. No. 61/524,543 filed Aug. 17, 2011, by applicants Austin Schreiber et al., and entitled AIR INLET FOR PATIENT SUPPORT DEVICE, the complete disclosure of which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to patient support devices, and more particularly to a system and method for coupling an air supply hose to an air inlet of an inflatable patient support device. 
         [0003]    Patient support devices often include an inflatable structure, such as an air mattress or the like, that is adapted to provide a cushioned support for supporting a patient. Such supports may be found on beds, stretchers, cots, and other support devices found in hospitals, nursing homes, and other places for patient care. Such inflatable supports may also be used as part of a patient transfer device in which the inflatable cushion includes a plurality of air passageways on its bottom surface that, when coupled to a source of pressurized air, create an air cushion underneath the transfer device. The air cushion reduces the frictional resistance between the inflatable cushion and the underlying surface, thereby allowing the patient and cushion to slide more easily. Such improved sliding allows a patient to be more easily transferred from one surface to another. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention relates to systems and methods for coupling and decoupling a hose from a source of fluid, such as air, to an inlet into the inflatable patient device. The systems and methods facilitate the easy coupling and decoupling of the hose to the inlet. Further, the various embodiments of the systems and methods enable the air inlet to be stowed in a compact position, to be more easily used and/or cleaned, to be less susceptible to contamination, and to expedite the coupling and decoupling of the air supply hose to the air inlet. 
         [0005]    According to one aspect of the invention, an inflatable patient support device is provided. The support includes a flexible body and an air inlet coupled thereto. The flexible body is adapted to be inflated and deflated and to support a patient on a top surface thereof. The air inlet includes a plurality of resilient members positioned near an opening defined in the air inlet. The resilient members bias the opening toward a first position in which the inlet assumes a flat orientation. The resilient members also flex away from each other toward a second, non-flat position when a compressive force is applied to the inlet substantially parallel to a longitudinal extent of the resilient members. 
         [0006]    According to another embodiment, an air inlet for an inflatable patient transfer device is provided. The inflatable patient transfer device includes a flexible body adapted to be inflated and deflated, wherein the body includes an underside and a top side and the underside has a plurality of air passages adapted to allow air from inside the body to escape to generate an air cushion underneath the flexible body. The top side is adapted to support a patient thereon. The air inlet includes first and second substantially planar surfaces that are positioned opposite from each other and which each have first and second sides. The first and second sides of the first surface are coupled to the first and second sides of the second planar surface. The first and second surfaces are adapted to flex between a first position in which the first and second surfaces are substantially flat and parallel to each other and a second position in which the first and second surfaces form a curved shape sized to accept an air supply hose between the first and second surfaces. 
         [0007]    According to still another embodiment, a method is provided for using an air inlet of an inflatable patient support device and an air supply hose. The method includes applying a compressive force to opposite sides of the air inlet until the air inlet flexes from a substantially flat shape into a curved shape having an opening sized to receive the air supply hose. The method further includes inserting the air supply hose into the opening until a collar defined on the air supply hose moves past an edge defined in an interior of the inlet, and terminating the compressive force in order to allow the edge to engage a portion of the collar to thereby resist removal of the air supply hose from the air inlet. 
         [0008]    According to still other embodiments, the resilient members may be leaf springs, and the leaf springs may be made from a thermoset urethane. The air inlet may include a first tubular section adjacent the opening and a second tubular section adjacent the first tubular section wherein the second tubular section has an inside diameter less than an inside diameter of the first tubular section. A plurality of magnets may be positioned adjacent the opening and the magnets may be arranged such that a magnetic force urges the resilient members toward the first, closed position. The magnets may be positioned together with the resilient members as laminates. The air inlet may further include a plastic, releasable seal that includes a first and second half, wherein the first and second half are adapted to releasably engage each other in an airtight manner. The resilient members may further includes an interior surface defining an edge that engages a collar on the air hose when the air hose is inserted into the inlet, wherein the edge prevents withdrawal of the hose out of the inlet when the compressive forces are relaxed or terminated. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of an air inlet according to one embodiment shown in a flat orientation; 
           [0010]      FIG. 2  is a plan view of the air inlet of  FIG. 1 ; 
           [0011]      FIG. 3  is a sectional view of the air inlet of  FIG. 2  taken along the line III-III; 
           [0012]      FIG. 4  is a perspective view of an air supply hose and the air inlet wherein the air inlet has been squeezed into a non-flat orientation; 
           [0013]      FIG. 5  is a perspective view of the air supply hose and air inlet coupled together; 
           [0014]      FIG. 6  is a longitudinal sectional view of the air supply hose and air inlet when coupled together; 
           [0015]      FIG. 7  is a perspective view of an air inlet according to an alternative embodiment; 
           [0016]      FIG. 8  is a perspective view of an illustrative inflatable patient transfer device into which any of the air inlet embodiments may be incorporated; 
           [0017]      FIG. 9  is a perspective view of a pair of patient support devices illustrating how the patient support device of  FIG. 8  may be used to transfer a patient from one of the patient support devices to the other; and 
           [0018]      FIG. 10  is a sectional view of patient support device with a pair of air inlets, one of which is coupled to an air hose and the other of which is not. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0019]    An air inlet  20  according to one embodiment of the invention is depicted in  FIG. 1 . While not illustrated in  FIG. 1 , air inlet  20  is adapted to be incorporated into an inflatable patient support device, such as, but not limited to an air mattress, a patient transfer device that travels on an air cushion, or any other type of patient support device that utilizes pressurized air for providing support to one or more portions of a patient&#39;s body. Air inlet  20  includes a proximal end  22  and a distal end  24 . Proximal end  22  attaches to the air mattress or other patient support device and may extend partially into the interior of the patient support device, as will be discussed more below. Distal end  24  is adapted to receive an air supply hose, as will also be discussed in greater detail below. Air inlet  20  further includes a first side  26 , a second side  28 , a top surface  30 , and a bottom surface  32 . In the illustrated embodiment, air inlet  20  also includes a larger tubular section  34  and a smaller tubular section  36 . Smaller tubular section  36  is positioned adjacent proximal end  22 , while larger tubular section  34  is positioned adjacent distal end  24 . 
         [0020]      FIG. 2  is a plan view of air inlet  20 . As shown therein, air inlet  20  includes a plurality of resilient members  38  positioned adjacent distal end  24  and inside of air inlet  20 . As indicated by the dashed lines of  FIG. 2 , resilient members  38  are not visible externally of air inlet  20 , but instead are enclosed in the material of air inlet  20 , as will be discussed in greater detail below. 
         [0021]    The position, orientation, and size of resilient members  38  can be seen in more detail in  FIG. 3 , which is a cross-section taken along the lines III-III of  FIG. 2 . In the embodiment illustrated in  FIG. 3 , there are two resilient members  38   a  and  38   b . Resilient members  38  have a longitudinal dimension that extends substantially from first side  26  to second side  28  of air inlet  20 . Resilient members  38  may be leaf-springs, or other types of structures that are flexible enough to bend into a curved shape sized to accept an air supply hose and thereafter substantially return to the generally flat orientation depicted in  FIG. 3 . The material of resilient members  38  may vary widely. In some embodiments, resilient members  38  may be made from steel, beryllium, copper, plastic, or other materials. In at least one embodiment, resilient members  38  are made from a thermoset urethane. 
         [0022]    Resilient members  38 , in the illustrated embodiment, have a perimeter defined by a generally rectangular shape and have a thin, generally planar body. The generally planar body of the resilient members  38  is parallel to the generally planar top and bottom surfaces  30  and  32  of air inlet  20 . It will be understood by those skilled in the art that the shape, size, and construction of resilient members  38  can vary from that illustrated in the accompanying drawings. It will also be understood by those skilled in the art that the placement and number of resilient member  38  can vary from what is shown in the attached drawings. For example, instead of a pair of resilient members  38 , it would be possible to modify air inlet  20  such that resilient members  38   a  and  38   b  were connected together to thereby form a single resilient member  38  having a ring-like shape that was flexible between the flat orientation of  FIGS. 1 and 3  and the open orientation of  FIG. 4 . Alternatively, more than two resilient members  38  could be positioned inside of air inlet  20 . 
         [0023]      FIG. 3  also illustrates a pair of magnets  40 . Each magnet  40  is laminated together with an adjacent resilient member  38 . Magnets  40  are oriented such that a magnetic force of attraction exists between the magnet  40  positioned along top surface  30  and the magnet  40  positioned along bottom surface  32 . Thus magnets  40  are positioned such that the attractive magnetic force between magnets  40  tends to close off distal end  24  and maintain air inlet  20  in the flat orientation depicted in  FIGS. 1 and 3 . The magnetic polar arrangement of magnets  40  may take on any suitable orientation that achieves the attractive force that biases air inlet  20  toward the flat orientation. A greater or lesser number of magnets  40  may alternatively be used. 
         [0024]    In the embodiment illustrated in  FIG. 3 , magnets  40  are elongated strips generally sized similar to the size of resilient members  38 . Each magnet  40  of  FIG. 3  is laminated together with a corresponding resilient member  38 . Thus, one magnet  40  and one resilient member  38  together form a first upper laminate  42 , and another resilient member  38  and magnet  40  together form a second lower laminate  44 . The means by which magnet  40  and resilient members  38  are laminated together may take on any suitable known means for lamination. Such means may include radio frequency welding, adhesives, other types of welding, or any other suitable methods for securing magnets  40  and resilient members  38  into laminate pairs. In other alternative embodiments, magnets  40  and resilient members  38  may be positioned in configurations wherein a space exists between each of the magnets  40  and each of the resilient members  38 . For example, magnets  40  may be positioned in a location that is off set from resilient members  38 . Such off setting may be in the direction parallel to a line connecting proximal end  22  to distal end  24 . Alternatively, magnets  40  may be off set from resilient members  38  in other manners. 
         [0025]    It will also be understood by those skilled in the art that the size and shape of magnets  40  may vary substantially from that shown in the accompanying drawings. For example, magnets  40 , as illustrated, are substantially the same shape and size as resilient members  38 . This may be altered. Thus, magnets  40  could be made smaller than resilient members  38 , or they could be made larger. Magnets  40  could also have shapes that are different than those of resilient members  38 . Magnets  40  could therefore be circular, curved, or otherwise non-rectangular. Still other variations are possible. Magnets  40  could also be entirely eliminated in at least some embodiments of air inlet  20 . 
         [0026]    The purpose of magnets  40 , when present, is to help return air inlet  20  to the closed position illustrated in  FIGS. 1 and 3 . While resilient members  38  also urge air inlet  20  to the closed position, resilient members  38  may, over time, become set in a shape that is not perfectly flat. Thus, resilient members  38  may, over time, take on a permanent bend that fails to urge surfaces  30  and  32  completely back to the flat orientation when compressive forces are no longer applied to sides  26  and  28 . Magnets  40  help ensure that when air inlet  20  is not in use, top and bottom surfaces  30  and  32  completely return to the closed position, thereby returning air inlet  20  to a substantially flat orientation. 
         [0027]    It will of course be understood by those skilled in the art that magnets  40  are an optional component of air inlet  20 . That is, air inlet  20  can be practiced, in some embodiments, without the use of any magnets  40 , or any equivalent structures. Air inlet  20  could, therefore, be manufactured with just resilient members  38  and no magnets  40 . As another alternative, structures other than magnets  40  could be used to help ensure that resilient members  38  return completely to the flat orientation. Such other structures may include a Velcro seal, a zipper, one or more snaps, a releasable plastic seal of the type commonly found on conventional plastic sandwich bags, or other structures serving similar functions. 
         [0028]      FIG. 4  illustrates air inlet  20  in an open position wherein air inlet  20  is able to receive an air supply hose  46 . Air inlet  20  is moved from the closed position of  FIGS. 1 and 3  to the open position of  FIG. 4  by applying a compressive force to first and second sides  26  and  28 . The direction of the compressive force is illustrated in  FIG. 4  by arrows  48 . The compressive force is applied to first and second sides  26  and  28  of air inlet  20  generally near the ends of resilient members  38 . The compressive force causes the resilient members  38  to flex out of their generally flat orientation into curved orientations. More specifically, resilient member  38   a  flexes into a curved shaped that extends away from the curved shape of resilient member  38   b . This creates an opening  50  at distal end  24 . Opening  50  is sized sufficiently large enough to receive air supply hose  46 . A center  52  of resilient member  38   a  will increase its vertical separation from center  52  of resilient member  38   b  when compressive force is applied in the direction of arrows  48 . Therefore, a user of air inlet  20  need only squeeze first and second sides  26  and  28  with a force sufficient to space apart centers  52  such that sufficient vertical separation exists to accept air supply hose  46 . Air inlet  20  is manufactured sufficiently large such that the horizontal spacing between first and second sides  26  and  28  can accept air supply hose  46 , even after the compressive force has moved sides  26  and  28  toward each other to create vertical space between surfaces  30  and  32 . 
         [0029]    Air supply hose  46  in the illustrated embodiment includes a collar  54  that extends around the circular periphery of hose  46 . Collar  54  is positioned generally a short distance away from an end  56  of hose  47 . As will be explained in further detail below, collar  54  is used to help secure hose  46  to air inlet  20  after air inlet  20  and hose  46  are coupled together. 
         [0030]    In order to couple air inlet  20  to air supply hose  46 , a user applies a compressive force to first and second sides  26  and  28  in the direction indicated by arrows  48  ( FIG. 4 ). This compressive force is applied at a sufficient level to cause a vertical separation between centers  52  of resilient members  38  that is large enough to accept hose  46 . Thereafter, hose  46  is inserted into opening  50  in the direction indicated by arrow  58 .  FIG. 5  provides an illustration of air supply hose  46  after it has been inserted into opening  50  of air inlet  20  and coupled thereto. As can also be seen in  FIG. 5 , hose  46  has been inserted into air inlet  20  sufficiently far such that collar  54  is positioned completely inside of larger tubular section  34  of inlet  20 . Once supply hose  46  has been sufficiently inserted into air inlet  20 , the user releases the first and second sides  26  and  28  and no longer needs to apply a compressive force. With the termination of the compressive force, the natural tendency of resilient members  38  to return toward their flat orientation will cause resilient members  38  to grip hose  46 . Further, as can be more easily seen with respect to  FIG. 6 , and as will be discussed more below, the interaction of resilient members  38  with collar  54  prevents hose  46  from being removed from air inlet  20  in the absence of sufficient compressive forces being applied to sides  26  and  28  in the direction of arrows  48 . 
         [0031]      FIG. 6  illustrates a cross section of air inlet  20  and air supply hose  46  when the two are coupled together. As can be seen, collar  54  includes a rear surface  60  that is generally perpendicular to the longitudinal extent of hose  46 . Further, upper and lower laminates  42  and  44  both include an inner edge  62  that is oriented generally parallel to rear surface  60  of collar  54 . In the absence of compressive forces being applied to first and second sides  26  and  28 , inner edges  62  will abut against rear surface  60  of collar  54  when hose  46  is pulled in the direction of arrow  64  of  FIG. 5 . Stated alternatively, the frictional interference of inner edge  62  with rear surface  60  of collar  54  prevents hose  46  from being withdrawn out of air inlet  20  in the absence of sufficient compressive forces being applied to first and second sides  26  and  28 . Therefore, if a user stops supplying compressive forces to first and second sides  26  and  28  after hose  46  has been inserted into air inlet  20 , hose  46  is prevented from being withdrawn. 
         [0032]    As can more clearly be seen in  FIG. 6 , air supply hose  46  includes a nozzle portion  66  positioned between end  56  of hose  46  and collar  54 . When hose  46  is inserted into inlet  20 , nozzle portion  66  gets at least partially inside smaller tubular section  36 . The outer diameter of nozzle portion  66  is substantially similar to the inner diameter of smaller tubular section  36 . There is, therefore, relatively little play between the material of inlet  20  in smaller tubular section  36  and nozzle portion  66 . While the contact between nozzle portion  66  and smaller tubular section  36  does not need to form an air tight seal, it may be desirable to avoid substantially large gaps between nozzle portion  66  and the material of inlet  20  in smaller tubular section  36 . Nozzle portion  66  may be, in several embodiments, tapered in order to fit into smaller section  36 . In other embodiments, nozzle portion  66  need not be tapered. 
         [0033]    When air is pumped through air supply hose  46  into inlet  20  in the direction indicated by arrow  68  of  FIG. 6 , the fluid dynamics of the moving air tend to draw the material of smaller tubular section  36  tightly against nozzle portion  66 . Relatively little, if any, air pumped by supply hose  46  escapes out of opening  50  of air inlet  20 . Instead, substantially all of the air supplied by hose  46  will flow into air inlet  20  and the attached air mattress, or other inflatable device coupled to air inlet  20 . 
         [0034]      FIG. 6  illustrates one manner in which resilient members  38  and magnets  40  may be secured to inlet  20 . As shown in  FIG. 6 , the material of inlet  20  is folded over adjacent opening  50  and secured to itself at a seam  70 . In the example of  FIG. 6 , seam  70  is on the interior of air inlet  20 . Seam  70  could, alternatively, be on the exterior of air inlet  20 . Still further, seam  70  could be positioned in other locations. In still other embodiments, resilient members  38  and/or magnets  40  may be attached to air inlet  20  in other fashions that would not involve the seams. 
         [0035]      FIG. 7  illustrates an alternative air inlet  120 . Air inlet  120  differs from inlet  20  in that air inlet  120  includes a releasable seal  72  positioned between distal end  24  and resilient members  38 . The remaining construction of inlet  120  is the same as air inlet  20 , and like numbered elements are used to identify these common components. Releasable seal  72  may be an air tight seal that can be opened and closed during use and non-use, respectively. Releasable seal  72  may be a plastic rib and groove type seal commonly found in conventional sandwich bags, kitchen bags, and the like. One example of such a releasable seal includes the releasable seal found on plastic bags sold under the Zip-Loc trademark. Other types of releasable seals may also be used. Such releasable seals may include a first half attached to the underside of top surface  30  and a second half attached to the top side of bottom surface  32  wherein the two halves are releasably sealable together. After air inlet  20  is done being used, releasable seal  72  may be sealed in order to prevent air from entering into opening  50 . This helps prevent any infectious materials or contaminants from potentially entering the interior of air inlet  20 . When it is time to use air inlet  20 , releasable seal  72  is pulled apart, thereby providing access to opening  50 . 
         [0036]    In other embodiments, releasable seal  72  may be constructed out of different materials besides plastic ribs and grooves. Still further, in some embodiments, releasable seal  72  need not be constructed to provide an air-tight seal when closed. Thus, releasable seal  72  could, in some embodiments, be made from Velcro, a zipper, one or more snaps, or the like. 
         [0037]      FIG. 8  illustrates one embodiment of a patient support  74  to which any of the various embodiments of air inlets  20  and  120  may be coupled. Patient support  74  of  FIG. 8  is a transfer device that assists in transferring a patient laterally from one surface to another surface. For example, as illustrated in  FIG. 9 , patient support  74  may be used to transfer a patient from a first bed  76  to a second bed  78 . Patient support  74  assists in the lateral transfer of the patient from a first surface to a second surface by creating an air cushion on the underside of patient support  74 . This air cushion reduces the frictional resistance that otherwise resists horizontal sliding of support  74 . Further details regarding the construction and operation of one example of such a patient transfer device can be found in U.S. patent application Ser. No. 11/801,007 filed May 8, 2007 by Richard DeLuca et al. and entitled Air Bearing Pallet, the complete disclosure of which is hereby incorporated herein by reference. Additional details regarding the construction and operation of another embodiment of patient support device  74  may be found in U.S. patent application Ser. No. 12/554,431 filed Sep. 4, 2009 by Schreiber et al, entitled Patient Transfer Device, the complete disclosure of which is also hereby incorporated herein by reference in its entirety. 
         [0038]    Patient support  74  includes a top surface  80  and a bottom surface  82 . Top surface  80  is adapted to support a patient thereon. If support  74  is constructed to assist in patient transfer through the use of an air cushion, bottom surface  82  will include a plurality of perforations or holes (not shown) out of which pressurized air may escape when patient support  74  is inflated. This escaping air creates an air cushion on the underside of patient support  74 , thereby reducing frictional resistance to lateral motion. Patient support  74  may also include a plurality of straps  84  for securing a patient thereto. 
         [0039]    In order to use patient support  74 , it must first be inflated. As illustrated in  FIG. 8 , a air source  86 , which may be a pump, a blower, or the like, is connected to air inlet  20  or  120  of patient support  74 . Air supply hose  46  of air source  86  inserts into air inlet  20  or  120  in the manner previously described. Once inserted, air flows from source  86  into the interior of patient support  74 , thereby inflating the support. If used to transfer a patient on an air cushion, air will continue to flow into patient support  74  while the patient is transferred from one surface to another. After the patient transfer is complete, the pressurized air, source  86  may be turned off and air hose  46  removed from air inlet  20  or  120 . This removal is accomplished in the manner discussed above. That is, a user squeezes first and second sides  26  and  28  of inlet  20 , thereby expanding opening  50  a sufficient amount to allow hose  46  to be retracted out of opening  50 . 
         [0040]    Air inlet  20  can also be used on patient supports that are not adapted to transfer patients from one surface to another. As one example, air inlet  20  can be used on inflatable mattresses which are not adapted to provide an air cushion for facilitating the sliding movement of the support. Air inlet  20  and  120  may also be used as an inlet into other inflatable devices, other than patient supports. 
         [0041]    Air inlet  20 , in its various embodiments, provides a quick and easy way of coupling and de-coupling air supply hose  46  thereto. Such coupling does not require any twisting movement or complex alignment of parts. Further, air inlet  20  easily and reliably returns to its flat orientation when not in use. Its flat orientation enables air inlet  20  to occupy less space and to be more easily stowed. Because air inlet  20  is made from a flexible material, patient support  74  can be rolled, folded, or otherwise compacted into a small amount of space. Air inlet  20  also does not provide a physically hard structure that may provide discomfort to a patient located on patient support  74 , even when patient support  74  is not inflated. 
         [0042]    In at least some embodiments of the patient support, more than one air inlet  20  or  120  may be incorporated into the patient support. An example of an illustrative patient support  174  having multiple air inlets is shown in  FIG. 10 . Patient support  174  includes a first air inlet  20   a  attached to a first side  90  of support  174 , and a second air inlet  20   b  attached to a second side  92  of support  174 . Patient support  174  is depicted in  FIG. 10  in a sectional view in order to illustrate one example of how the components of air inlets  20   a  and  b  that extend inside of support  174  may be constructed. For example, each air inlet  20  in the example of  FIG. 10  includes an extension  96  that extends into the interior of patient support  174 . Extensions  96  may be made of the same flexible material as the rest of air inlets  20  and/or  120 , or they may be made of other material. Extensions  96  serve to create a check valve effect for the air inlet that is not currently receiving air from an air supply hose  46 . For example, in the illustration of  FIG. 10 , air inlet  20   b  is not attached to an air hose  46  while air inlet  20   a  is. Extension  96  of air inlet  20   b  extends downwardly and effectively blocks off access to air inlet  20   b  from the interior of patient support  174 . That is, air inside of patient support  174  is prevented by extension  96  from escaping through inlet  20   b . The pressure of the air inside patient support  174  helps push extension  96  against the wall of support  174 , thereby maintaining the air-tight blockage of air inlet  20   b.    
         [0043]    In contrast, the air inlet  20   a  that is currently being used is not affected by extension  96 . That is, the air flowing through hose  46  has sufficient pressure to push extension  96  out of the way and allow air to enter into the interior of support  174 . Once the blower or pump that is attached to hose  46  is shut off, the flow of air through hose  46  ceases, and the pressure exerted against extension  96  of air inlet  20   a  by the formerly inflowing air ceases. This allows extension  96  to drop against the wall of support  174 —aided by the air pressure inside of support  174 —thereby automatically sealing air inlet  20   a  against air leakage out of support  174 . Air inlet  20  will therefore automatically self-seal when air ceases to flow through hose  46 . It will, of course, be understood by those skilled in the art that the shape, construction, and overall configuration of extensions  96  may be varied substantially from that illustrated in  FIG. 10 . 
         [0044]    Air inlet  20  may be manufactured from a flexible material, such as a suitable plastic or plastic-coated fabric that is generally air impermeable. This prevents air from escaping through the material of air inlet  20 , while allowing air inlet  20  to be compressed into a flat orientation when not in use. Additional examples of the types of material out of which inlet  20  may be constructed may be found in the two patents referenced above and incorporated herein by reference. 
         [0045]    The foregoing embodiments of the invention are exemplary and can be varied in many ways, and, further, features of one embodiment may be combined with features of another embodiment and used in combination with features of more than one embodiment. Such feature variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be including within the scope of the following claims.