Abstract:
A check valve for an inflatable device comprising a poppet urged by a conical spring to annularly seal uniformly around its entire periphery to assure more uniform cracking pressure about its entire periphery. In one embodiment the check valve comprises a locking key to lock the valve closed irrespective of the cracking pressure that may otherwise may have cracked the valve open. In another embodiment, the check valve comprises a manual dump feature that allows rapid dumping of air from the inflatable irrespective of low cracking pressure that may exist in the inflatable.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of patent application Ser. No. 10/935,937, filed Sep. 8, 2004, now U.S. Pat. No. 7,096,884, the disclosure of which is hereby incorporated by reference herein. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     This invention relates to check valves. More particularly, this invention relates to check valves having presettable and adjustable cracking pressures.  
         [0004]     2. Description of the Background Art  
         [0005]     Presently, there exist many types of check valves designed to allow the flow of a fluid such as a gas in one direction but to block or “check” the flow of the fluid in the opposite direction. The amount of fluid force required to open the poppet of the valve in the un-checked direction is often referred to as the cracking pressure. Typically, the cracking pressure of a check valve is determined by the spring constant of the internal spring which constantly urges the poppet into a sealing position until unseated therefrom once the cracking pressure is attained.  
         [0006]     A predetermined cracking pressure of a check valve is desired when check valves are used in conjunction with inflatable articles such as life vests and life rafts. Specifically, a check valve having a predetermined cracking pressure allows the inflatable to be inflated by means of a gas cartridge or the like to assure that the inflatable is inflated to a preset internal pressure. Thus, by allowing excess gas to be exhausted, over-capacity gas cartridges can be employed to inflate the inflatable to ensure that the inflatable is fully inflated to a preset internal pressure in all environments.  
         [0007]     Whereas in some applications a preset cracking pressure is desired, in other applications it is desirable to have a check valve with a variable cracking pressure. A check valve with a variable cracking pressure may be desired, for example, in an inflatable device such as a life vest to achieve a certain amount of buoyancy or when a certain rigidity is desired. Further, in still other applications such as when transporting an inflatable, it is desirable to be able to “lock” the check valve from opening irrespective of the amount of cracking pressure in the inflatable. Finally, it may be desirable in still other applications to be able to manually open the check valve to quickly “dump” air from an inflatable. Thus, there presently exist various needs in the check valve industry for a check valves with fixed cracking pressures, with variable cracking pressures, with a locking feature and/or with a dumping feature.  
         [0008]     Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the check valve art.  
         [0009]     Another object of this invention is to provide a check valve having an increased flow rate.  
         [0010]     Another object of this invention is to provide a check valve having a structure composed of a minimal number of parts to increase its reliability while decreasing cost of manufacture and assembly.  
         [0011]     Another object of this invention is to provide a check valve having a design that equalizes the sealing force of the poppet around its entire periphery to assure that the check valve is cracked uniformly about the periphery of the poppet.  
         [0012]     Another object of this invention is to provide a check valve with a fixed cracking pressure.  
         [0013]     Another object of this invention is to provide a check valve with a with a variable cracking pressure.  
         [0014]     Another object of this invention is to provide a check valve with a locking feature to prevent cracking of the check valve irrespective of the pressure exerted that would otherwise crack valve open.  
         [0015]     Another object of this invention is to provide a check valve with a manual dumping feature that allows the valve to be manually cracked open.  
         [0016]     The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.  
       SUMMARY OF THE INVENTION  
       [0017]     For the purpose of summarizing this invention, this invention comprises a check valve having a simple design with fewer parts than conventional prior art check valves to achieve increased reliability while reducing manufacturing and assembly costs. The check valve of the invention further achieves an increased flow rate upon cracking due to its simplistic yet ingenious design.  
         [0018]     Finally, the poppet of the check valve of the invention cooperates with a conical spring to assure that it seals uniformly around its entire periphery facilitating more uniform cracking pressure about its entire periphery.  
         [0019]     In another embodiment of the check valve of the invention, the cracking pressure is adjustable by means of a threaded adjustable plate which cooperates with the conical spring to reduce the length thereof and thereby increase the amount of force exerted by the spring onto the poppet into sealing engagement, thereby increasing the cracking pressure.  
         [0020]     In still another embodiment, the check valve of the invention comprises a removable locking key that engages the poppet to preclude it from cracking open irrespective of the cracking pressure exerted on it that would otherwise crack the valve open.  
         [0021]     In a further embodiment, the check valve of the invention comprises a manual dump plate including a tether with a pull handle coupled to the spring that cracks the poppet open by releasing the spring force that otherwise would force it closed, thereby unseating it from its seat upon pulling of the handle of the tether. The manual dump plate allows manual cracking of the valve open to dump the air from the inflatable device irrespective of low cracking pressure in the inflatable that would otherwise be insufficient to crack the valve open.  
         [0022]     The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:  
         [0024]      FIG. 1  is a perspective view of the first embodiment of the check valve of the invention;  
         [0025]      FIG. 2  is a perspective view, partially cut-away, of the first embodiment of the invention;  
         [0026]      FIG. 3  is a diametrical cross-sectional view of the first embodiment of the invention;  
         [0027]      FIG. 4  is a perspective view of the second embodiment of the check valve of the invention;  
         [0028]      FIG. 5  is a diametrical cross-sectional view of  FIG. 5  along lines  5 - 5 ;  
         [0029]      FIG. 6  is a partial diametrical cross-sectional view of the second embodiment but with an alternative manner for centering the conical spring to assure uniform sealing of the poppet;  
         [0030]      FIG. 7A  is a diametrical cross-sectional view of the check valve of the invention having a locking key to lock the valve closed and prevent it from opening irrespective of the cracking pressure exerted on it;  
         [0031]      FIG. 7B  is an exploded view of  FIG. 7A ;  
         [0032]      FIG. 7C  is a perspective view of the locking key of  FIG. 7A ;  
         [0033]      FIG. 7D  is a top plan view of the cap showing the notches formed in the slotted hole that receives the locking key;  
         [0034]      FIG. 8A  is an exploded view of the check valve of the invention having a manual dump plate to allow opening of the poppet of the valve irrespective of the cracking pressure exerted on it thereby allowing the dumping of air in the inflatable to which the valve is installed;  
         [0035]      FIG. 8B  is an exploded perspective view of the manual dump plate and poppet. 
     
    
       [0036]     Similar reference characters refer to similar parts throughout the several views of the drawings.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0037]     In one embodiment, the check valve  10  of the invention comprises a body  12  having an upper body  12 U and a lower body  12 L threadably coupled together by complementary respective threads  12 T. A cap  14  is coupled to the upper body  12 U. Cap  15  comprises a plurality of flow openings  16  about its periphery allowing internal fluid such as air to flow in the direction of arrows  18  through the body  12  to then be exhausted from the check valve  10  via openings  16  as shown by arrows  20 .  
         [0038]     Body  12  may be connected about an opening in an inflatable, shown in phantom by reference numeral  22 , through the use of a complementary flanges  24  of the upper and lower bodies  12 U and  12 L that sealingly capture the edge  26  of the opening in the inflatable  22  as the bodies  12 U and  12 L are tightly threaded together. Alternatively, the lower body  12 L may comprise a heat-sealable flange  24  that is sealed about the edge  26  of the opening in the inflatable  22 . Representative heat-sealable flanges are disclosed in U.S. Pat. Nos. 2,219,190, 4,015,622, 4,927,397 and 6,009,895, the disclosures of each of which are hereby incorporated by reference herein.  
         [0039]     As shown in  FIGS. 2 and 3 , check valve  10  of the invention comprises a poppet  30  having an annular groove  32  in which is positioned an annular O-ring  34  that seats on an annular seat  36  formed at the end of the lumen  38  of the upper body  12 U.  
         [0040]     The poppet  30  includes a generally concave portion  46  having an upstanding protrusion  42  extending from the inside center thereof. Protrusion  42  comprises four interior webs  42 W positioned at 90 degree intervals and forming a semi-spherical outer configuration. Poppet  30  further comprises three exterior webs  44  positioned at 120 degree intervals and being slightly tapered inwardly from the lumen  38  of the body  12 .  
         [0041]     Cap  14  comprises a plurality of tabs  14 T that snap into corresponding slots formed in the outer periphery of the cap  12  to securely retain the cap  14  into position. Cap  14  further comprises a plurality of downwardly extending legs  14 L, such as three positioned at 120 degree intervals, to entrain and center the poppet  30  therebetween. The legs  14 L coupled with the exterior webs  44  assure that the poppet  30  may reciprocate upwardly within cap  14  without tilting sideways out of alignment where it might otherwise potentially jam.  
         [0042]     Finally, the check valve  10  of the invention comprises a conical spring  50  having its uppermost largest diameter coil  50 L captured by an annular step  14 S formed in the underside of the cap  14 . The lowermost smallest diameter coil  50 S is dimensioned to be appreciably less in diameter than the outer diameter of the protrusion  42  such that when the coil  50 S is seated thereon, poppet  30  is allowed to pivot universally in all directions. The ability of the poppet  30  to pivot universally by virtue of the protrusion  42  pivoting within the coil  50 S, assures that the O-ring  34  of the poppet  30  will be forced into sealing engagement with the annular seat  36  in a highly uniform manner about its entire periphery. Consequently, uniform cracking of the poppet  30  about its entire periphery is achieved.  
         [0043]     Referring now to  FIGS. 4 and 5 , the second embodiment of the check valve  10  of the invention comprises a similar body  12  with a cap  14  having flow openings  20  allowing fluid flow  18  to flow through the valve  10  in the unchecked flow direction. Similarly, the second embodiment of the check valve  10  of the invention comprises a conical spring  50  entrained between the cap  14  and a poppet  30  to urge its O-ring  34  in sealing engagement with the annular seat  36 .  
         [0044]     The poppet  30  further includes exterior webs  44  which prevent the poppet from becoming canted with the lumen  38 . However, due to the specific configuration of the cap  14 , in the second embodiment, the downward depending legs  14 L of the cap  14  of the first embodiment need not be included since the annular groove  32  moves in alignment with the lumen  52  of the cap  14 .  
         [0045]     In the second embodiment, poppet  30  similarly includes an upstanding center protrusion  42  with four webs  42 W forming an outer semi-spherical configuration on which is seated the lowermost smaller diameter coil  50 S of the spring  50 .  
         [0046]     Unlike the first embodiment, the second embodiment of the check valve  10  comprises an adjustable plate  60  having a center boss  62  with external threads  64  for threaded engagement with a threaded hole  66  formed in the center of the cap  14 . Boss  62  may be provided with a hex indentation  63  for receiving a hex or other tool.  
         [0047]     Plate  60  extends in a somewhat planar configuration from the boss  62  to a position between the uppermost larger diameter spring coil  50 L and the underside of cap  14 . Upon rotation of the boss  62  in a clockwise direction, plate  60  is caused to move inwardly to further compress the conical spring and thereby increase the cracking pressure of the check valve  10 . The outer periphery of the plate  60  may be provided with radial protuberances  60 P to engage into openings  20  and provide indexing of the plate  60  as the plate  60  is rotated to adjust the cracking pressure. The protuberances  60 P may be of the same width as the openings  20  or, if smaller, may be asymmetrically positioned to provide accurate indexing.  
         [0048]      FIG. 6  illustrates an alternative embodiment for free-floating of the poppet  30  to assure uniform annular indexing of its O-ring  34  on annular seat  36 . Specifically, protrusion  42  is configured to achieve a conical apex point for universal engagement into a corresponding center seat  72  formed in a balance plate  70 . The balance plate  70  assures that only a central force is exerted onto the poppet  30  thereby achieving uniform annular sealing.  
         [0049]     The various views of  FIG. 7  illustrate the check valve  10  of the invention incorporating a locking key  70  for fixedly locking the poppet  30  in its sealed, closed position seated on the annular seat  36  to thereby prevent the poppet  30  from cracking open irrespective of the internal pressure that would otherwise crack the poppet  30  against the force of the spring  50 .  
         [0050]     The locking key  70  comprises a generally circular cylindrical neck portion  72  and handle portion  74 , preferably integrally formed together such as by injection molding. The neck portion  72  of the locking key  70  is designed to fit within a slotted hole  78  formed in the center of the cap  14  (see  FIG. 7D ) to engage the center protrusion of the poppet  30  and then held from any upward movement by manually turning the neck portion  72  via its handle portion  74 , thereby fixedly locking the poppet  30  into its closed position.  
         [0051]     More particularly, the neck portion  72  comprises one or more locking protrusions  76  extending radially outward from the surface of its neck portion  72  in axial alignment with respective slotted notch(es)  78 N formed in the edge of the slotted hole  78 . Preferably, two notches  78 N are diametrically positioned across the hole  78  to form opposing notches  78 N. Likewise, preferably the locking protrusions  76  are correspondingly diametrically opposed on the neck portion  72  to thereby respectively fit into the opposing notches  78 N of the slotted hole  78 .  
         [0052]     It should therefore be evident that the outer diameter of the neck portion  72  is appreciably less than the inner diameter of a slotted hole  78  to fit therein whereas the outer diameter of the opposing protrusions  76  is appreciably less that the inner distance between the opposing notches  78 N.  
         [0053]     Once the neck portion  72  is inserted into the hole  78  and turned approximately  90  degrees, the locking protrusions  76  move from within the notches  78 N to the underside of the cap  14  about the periphery of the hole  78 . In this locked position, the neck portion  72  is locked in place and is prevented from any further axial movement relative to the hole  78 .  
         [0054]     The handle portion  74  preferably comprises a comfortable grip for a person&#39;s thumb and forefinger thereby facilitating insertion of the locking key into the hole  78  and then turning of the locking key  70  to fixedly lock it in the hole  78 . One comfortable grip may comprise a generally flat tapered design with a rounded top edge that is comfortable to grip by a person&#39;s thumb and forefinger. Further, the handle portion  74  may be marked with appropriate directional arrows to urge insertion and corresponding legends such as “LOCK”.  
         [0055]     The bottom end  80  of the neck portion  72  of the locking key preferably comprises a shallow axial blind hole  82  of a diameter sufficient to receive the upstanding protrusion  42  of the poppet  30  therein. Correspondingly, the length of the neck portion  72  preferably comprises a length sufficient to engage and exert a slight force onto the upstanding poppet protrusion  42  as the key  70  is inserted into the hole  78  and locked by twisting. Correspondingly, since the upstanding protrusion  42  is now locked from any further axial movement, the poppet  30  is locked in its seated potion on the annular seat  36  and the valve  10  is fixedly locked closed and cannot open irrespective of the cracking pressure that may be exerted on it.  
         [0056]     The locking key  70  may be removed by rotating it via its handle portion  74  until the locking protrusions  76  are again aligned with the notches  78 N whereupon the key  70  may be removed from the hole  78  altogether.  
         [0057]     Referring now to  FIG. 8 , the check valve  10  of the invention may include a manual dump feature that allows manual cracking of the valve open to dump the air from the inflatable device irrespective of low cracking pressure in the inflatable that would otherwise be insufficient to crack the valve open.  
         [0058]     More specifically, as shown in  FIGS. 8A and 8B , the manual dump feature comprises a dump plate  90  including a tether  92  with a pull handle  94 . The dump plate  90  comprises a thin disk-shaped configuration with a hollow center boss  96  having a center hole  98 . The tether  92  is coupled to the dump plate  90  by threading it through the center hole  98  and tying a knot  100  in its end. After tying the knot and pulling the tether  92 , the knot  100  is pulled into the hollow center boss  96 .  
         [0059]     As shown in  FIG. 8A , during assembly, the dump plate  90  is positioned between the poppet  30  and the spring  50 , with the tether  92  extending through the center of the spring  50  and then through a center hole  102  in the cap  14 . The pull handle  94  is then fixedly connected to the end of the tether  92 .  
         [0060]     Upon pulling of the pull handle  92 , an upward force is exerted onto the dump plate  90  which in turn causes the spring  50  to compress between the underside of the cap  14  and the dump plate  90 . Once the spring is compressed, it no longer exerts any force on the poppet  30 . The poppet  30  is therefore is unseated from its annular seat  36  (i.e., it is free floating). The inflatable is therefore “dumped” of any air since any air pressure within the inflatable is sufficient to move the poppet  30  significantly upwardly to allow such air to freely escape through the check valve  10 .  
         [0061]     The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and scope of the invention.  
         [0062]     Now that the invention has been described,