Abstract:
A release valve for connection to an inflatable cushion comprising an air conduit, a fitting at a first end of the air conduit for insertion into an air tube in fluid communication with the interior of the cushion, and an air inlet port at the opposite end of the air conduit and a filter assembly at the air inlet port. There is first, vertically orientated, spring biased ball valve centrally positioned in the air conduit including at least one air egress vent and being operatively associated with a spring biased actuator in the ball valve housing for opening the first ball valve. The button and first ball valve define a gap to minimize accidental air release. A second longitudinally orientated, spring biased ball valve is positioned in the air conduit adjacent the air inlet port.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application Ser. No. 61/969,993 filed Mar. 25, 2014 which is incorporated herein by reference. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    The application relates generally to valves for inflatable apparatus, more specifically, to a release valve for an inflatable seat cushion to bleed air from an inflated cushion to equalize pressure on various points of a seated user&#39;s anatomy. 
         [0004]    Inflatable seat cushions are well known. They are employed in all types of seating applications including vehicle seating. One particularly useful application of inflatable cushions, such as inflatable air cell cushions, is in motorcycle seating. In general, a motorcycle seat is constructed to support the seated rider&#39;s buttocks and, depending upon the size and style, a portion of the upper thigh. Most motorcycle seats or saddles are constructed from firm support padding or foam with a leather or vinyl covering. In use, the rider straddles the seat, thereby exposing the inner thigh, buttocks and genital area to pressure and vibration. If the rider is seated for long periods of time he can develop discomfort, soreness and even numbness in these regions of the anatomy due to pressure and vibration on the nerves. Furthermore, riders of other vehicles, such as bicycles, motor scooters and the like can suffer from similar discomforts. It is advantageous to have a seat cushion that provides support while relieving pressure on sensitive areas of the anatomy. This may be accomplished by incorporating an inflatable air cell cushion in or on the motorcycle seat. To function well for a wide variety of riders, the cushion needs to be adjustable. That is, the cushion should include a pump so that the rider can inflate the cushion. If the rider overinflates then he needs to bleed air out of the cushion until he reaches his comfort zone. Hence, it would be advantageous for the cushion to include a release valve. 
         [0005]    A release valve should be easy to use by a seated rider and should be well sealed so that vibration, bouncing and other pressures on the seat cushion do not cause it to leak air through the release valve, resulting in a deflated cushion. 
         [0006]    These advantages apply equally well to any vehicle seat or medical seating such as wheelchair cushions or inflatable mattresses. 
       SUMMARY OF THE INVENTION 
       [0007]    In one aspect, a release valve for connection to an inflatable cushion comprising an air conduit, a fitting at a first end of the air conduit for insertion into an air tube, the air tube being in fluid communication with the interior of the cushion, and an air inlet port at the opposite end of the air conduit. There may be a filter assembly at the air inlet port. There is first, vertically orientated, spring biased ball valve in a housing centrally positioned in the air conduit. The housing includes at least one air egress vent. The first ball valve is operatively associated with a spring biased actuator in the ball valve housing for opening the first ball valve. In one aspect, the actuator is a spring biased button. There is a gap or disconnect between the button and the ball valve to minimize the risk of accidental air release. There is a second longitudinally orientated, spring biased ball valve in the air conduit adjacent the air inlet port. 
         [0008]    In use, the cushion is inflated by pumping air through the filtered air inlet port. The pump creates sufficient pressure to overcome the bias strength of the spring to open the second ball valve and allow ingress of air through the air conduit and into the cushion. If the cushion is overinflated, the user depresses the button to overcome the biasing force of the spring, as well as to overcome the biasing force against the first ball valve to allow airflow from the cushion back through the first ball valve and out through vents in the first ball valve housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is one aspect of a cushion incorporating a release valve; 
           [0010]      FIG. 2  is a bottom side elevational view of a release valve; 
           [0011]      FIG. 3  is a perspective view thereof; 
           [0012]      FIG. 4  is another perspective view thereof; 
           [0013]      FIG. 5  is and end plan view thereof; 
           [0014]      FIG. 6  is a top plan view thereof; 
           [0015]      FIG. 7  a cross-sectional view taken along line  7 - 7  of  FIG. 6 ; 
           [0016]      FIG. 8  is an exploded view thereof; 
           [0017]      FIG. 9  is a cross-sectional view of a release valve showing inflation through the release valve; 
           [0018]      FIG. 10  is a cross-sectional view thereof showing bleeding air from a cushion; and 
           [0019]      FIG. 11  is a cross-sectional view thereof showing the release valve in a static state. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    One aspect of a release valve for an inflatable cushion is indicated generally be reference number  10  in the drawings.  FIG. 1  shows release valve  10  functionally attached to an inflatable motorcycle seat cushion, indicated generally by reference number  12  in the drawings. Although referred to as a motorcycle cushion for brevity and clarity, it will be appreciated the cushion can be employed with any seat, particularly, but not limited to, seats on vehicles, either self-propelled or motorized. The cushion can be an inflatable air cell cushion for medical or therapeutic use as well. Cushion  12  includes a base  14  with a plurality of upstanding air inflation cells  16  arranged in an array on the base. In one aspect, cells  16  are inflatable air cells and are generally hollow open-bottomed cells connected by a web which comprises the top layer of base  14 . In one aspect, the web and cell arrangement are dip molded from neoprene, as disclosed in U.S. Pat. No. 4,541,136, which is incorporated herein by reference. However, the web and cell arrangement may be formed in any acceptable manner from any acceptable material, such as cavity molded or dip molded plastic material or thermoformed plastic molding or any appropriate molding process. Moreover, the cells can be combinations of different cells, such as combinations of inflatable air cells with foam cells or gel filled cells as desired for modification of the support characteristics of the cushion. Cushion  12  could be one inflatable cell or bladder and not divided into separate inflatable cells. The salient point is that the cushion, or part of the cushion, is inflatable. 
         [0021]    As shown, release valve  10  is operatively associated with a hollow air tube  18 . Air tube  18  can be any length and is in fluid communication with air cells such that air can be introduced into the cushion for inflation through tube  18 . In the arrangement show, release valve  10  is positioned between the cushion and a pump  20 . Pump  20  is operatively associated with the release valve to pump air through the release valve and inflate the cushion. The illustrated pump  20  is a hand-operated bulb pump. However, any pump that functions appropriately to inflate the cushion will suffice. 
         [0022]    The elements of one aspect of release valve  10  are illustrated in  FIGS. 2 through 8 . Valve  10  comprises an elongated tubular air conduit  22  defining an inner bore  24 . A first end of air conduit  22  comprises a fitting  26  configured to fit snugly in an air tight arrangement with air tube  18  leading into the cushion. Fitting  26  can be affixed inside the air tube in any appropriate manner such as with a tight friction fit or glue or a tight retainer ring around the tubing. 
         [0023]    The second or opposite end of air conduit  22  comprises a fitting  28  configured and sized to fit securely with bulb pump  20 . It can be configured and sized to fit securely inside a tube  18  which in turn would be in fluid communication with a pump. Any arrangement will suffice as long as fitting  28  is associated with the pump  20 . 
         [0024]    As best seen in  FIGS. 7 and 8 , fitting  28  may include an associated filter  30  assembly. Filter assembly  30  is designed to capture grit or dirt or other materials that could enter valve  10  from the pump  20  or ambient air during inflation of the cushion and foul the working elements inside the valve. Filter assembly  30  has a tubular configuration defining an inner bore  32  with an internal filter element  33  end cap  34  to close it off. Bore  32  is in fluid communication with bore  24  of air conduit  22 . There is a circumferential O-ring seat  36  inside bore  32  adjacent the end. An O-ring  38  is positioned against seat  36 . A ball  40  is positioned within bore  32  against O-ring  38 . There is a bias spring  42  positioned between ball  40  and an internal circumferential shoulder  44  inside bore  24 . Spring  42  exerts a biasing force against ball  40  to force it against O-ring  38  to form an airtight seal within filter assembly  30 . It will be appreciated that the combination of O-ring  38 , ball  40  and spring  42  form a longitudinally disposed one-way ball valve. Also, the configuration of the O-ring, seat and end cap may be any useful configuration. For example, the O-ring may have a conventional circular cross-section or the O-ring may be flat, like a washer and of an appropriate thickness. Moreover, the hardness of the O-ring may be of any useful Durometer such that it functions well as intended to form a seal. 
         [0025]    There is a vertically disposed valve housing  45  at the approximate midpoint of air conduit  22 . As shown in the drawings, valve housing  45  comprises an open top cylindrical body  46  defining an internal chamber  48  on a first side of the air conduit. Cylindrical body  46  comprises a circumferential wall  49  that includes one or more vents  50  in fluid communication with chamber  48 . There is a cylindrical ball housing  52  on the opposite side of the air conduit defining an internal chamber  54 . It will be noted that chamber  48 , bore  24  and chamber  54  are in fluid communication with each other in use, as will be explained. 
         [0026]    There is a release button  56  positioned in the open top of cylindrical body  46  and extending into chamber  48 . Button  56  is slidingly engaged in chamber  48 . Button  56  includes a circumferential depending wall  58  with at least one groove  60  or other opening form in the wall. Button  56  also includes a concentric, vertical stem  62 . There is a snap-fit catch  63  in cylindrical body  46  to hold the button in place. This allows the button and stem to be one piece. A bias spring  64  is positioned around stem  62  and abuts the top side of shoulder  66 . Spring  64  normally urges button upwardly in chamber  48 . 
         [0027]    Cylindrical ball housing  52  comprises a circumferential wall  68  having ribs  70  for centering a ball and in a chamber  72 . Housing  52  is open ended, but in use is closed by a cap  74 . There is a ball  76  positioned in chamber  72  and centered by ribs  70 , a bias spring  78  between cap  74  and ball  76 , and an O-ring  80  seated against the bottom side of shoulder  66 . Bias spring  78  normally urges ball  76  against O-ring  80  to block air flow through vents  50  and maintain a constant pressure within the cushion. The spring, ball and O-ring together form a vertically disposed ball valve. It will be appreciated from the drawings, that release button  56 , and more particularly stem  62  is not physically connected to ball  72 . 
         [0028]      FIGS. 9 through 11  illustrate release valve  10  in various stages of use. Referring to  FIG. 9 , to inflate the cushion the pump is actuated and the force or air pressure generated by the pump over comes the biasing force of spring  42 , moving ball  40  away from O-ring  38  such that air can flow through bore  32 , air chamber  72 , bore  24  and into the cushion. 
         [0029]    If the cushion is over inflated, the user can bleed air through valve  10  as illustrated in  FIG. 10 . The user depresses release button  56  sufficiently to overcome the biasing force of spring  64 . Stem  62  engages ball  76  to urge it away from O-ring  80 . Air from the cushion flows through bore  24 , through chamber  72  and out through vents  50 . When proper or comfortable inflation is reached, the user releases button  56 . At stasis, that is, when the user releases button  56 , as shown in  FIG. 11 , ball  76  is biased against O-ring  80  to form a seal. Moreover, spring  42  biases ball  40  against O-ring  38  to form another airtight seal. 
         [0030]    The foregoing arrangement of elements exhibit several important features, among many. By way of example, the entire valve  10  can be constructed and hermetically sealed. Also, because release button  56  is not connected to ball  76 , inadvertent opening of the ball valve is avoided by bumping or touching the release button. The release valve can be conveniently manipulated by a seated user. The combination of two ball valves prevents air leakage from vibration of bouncing on the seat cushion. Many other advantages of the release valve will be recognized by those skilled in the relevant art. 
         [0031]    It will be appreciated that various changes and modification may be made in the motorcycle seat cushion of the present invention without departing from the scope of the invention. By way of example only, the cushion can have different configurations and be constructed in varying sizes so as to fit on different types of motorcycle saddles. The cushion and the cover can be constructed of different materials as well. The embodiment shown and described is intended to be illustrative of the broader aspects of the invention and should not be construed in a limiting sense.