Abstract:
A variably tensionable check valve with a first end and a second end that includes a housing, a tension adjuster, a resiliently deformable elastic member, and a flow restriction member biased in a closed position. The housing includes a first portion, a second portion, and first and second passageways with a transition portion therebetween. The second portion includes at least one peripherally extending raised rib and a second internal passageway. The surface area of a cross-section of the first internal passageway is greater than the surface area of a cross-section of the second internal passageway. The tension adjuster, the elastic member, and the flow restriction member are located within the first internal passageway, wherein the tension adjuster secures the elastic member and the flow restriction member within the first internal passageway, and wherein rotational movement of the tension adjuster modifies the biasing force of the elastic member.

Description:
TECHNICAL FIELD  
       [0001]    The invention described herein relates generally to foam spray guns that utilize a variably adjustable adaptor that prevents starting raw material crossover. 
       BACKGROUND OF THE INVENTION 
       [0002]    This invention is particularly suited for in-situ applications of liquid chemicals mixed and dispensed as a spray or a foam and more specifically, to in-situ application of polyurethane foam or froth. In-situ applications for polyurethane foam have continued to increase in recent years extending the application of polyurethane foam beyond its traditional uses in the packaging, insulation and molding fields. For example, polyurethane foam is being used with increasing frequency as a sealant in the building trades for sealing spaces between windows and door frames and the like and as an adhesive for gluing flooring, roof tiles, and the like. 
         [0003]    Polyurethane foam for in-situ applications is typically supplied as a “one-component” froth foam or a “two-component” froth foam in portable containers hand carried and dispensed by the operator through either a valve or a gun. However, the chemical reactions producing the polyurethane froth foam in a “one-component” polyurethane foam is significantly different from the chemical reactions producing a polyurethane froth foam in a “two-component” polyurethane foam. Because the reactions are different, the dispensing of the chemicals for a two-component polyurethane foam involves different and additional concepts and concerns than those present in the dispensing apparatus for a “one-component” polyurethane froth foam. 
         [0004]    A “one-component” foam generally means that both the resin and the isocyanate used in the foam formulation are supplied in a single pressurized container and dispensed from the container through a valve or a gun attached to the container. When the chemicals leave the valve, a reaction with moisture in the air produces a polyurethane froth or foam. Thus, the design concerns related to an apparatus for dispensing one-component polyurethane foam essentially concerns the operating characteristics of how the one-component polyurethane foam is throttled or metered from the pressurized container. Post drip is a major concern in such applications as well as the dispensing gun not clogging because of reaction of the one component formulation with air (moisture) within the gun. To address or at least partially address such problems, a needle valve seat is typically applied as close to the dispensing point by a metering rod arrangement which can be pulled back for cleaning. While metering can occur at the needle valve seat, the seat is primarily for shut-off to prevent post drip, and depending on gun dimensioning, metering may principally occur at the gun opening. 
         [0005]    In contrast, a “two-component” froth foam means that one principal foam component is supplied in one pressurized container, typically the “A” container (i.e., polymeric isocyanate, fluorocarbons, etc.) while the other principal foam component is supplied in a second pressurized container, typically the “B” container (i.e., polyols, catalysts, flame retardants, fluorocarbons, etc.). In a two-component polyurethane foam, the “A” and “B” components form the foam or froth when they are mixed in the gun. Of course, chemical reactions with moisture in the air will also occur with a two-component polyurethane foam after dispensing, but the principal reaction forming the polyurethane foam occurs when the “A” and “B” components are mixed or contact one another in the dispensing gun and/or dispensing gun nozzle. The dispensing apparatus for a two-component polyurethane foam application has to thus address not only the metering design concerns present in a one-component dispensing apparatus, but also the mixing requirements of a two-component polyurethane foam. 
         [0006]    Further, a “frothing” characteristic of the foam is enhanced by the pressurized gas employed, e.g., fluorocarbon (or similar) component, which is present in the “A” and “B” components. This fluorocarbon component is a compressed gas which exits in its liquid state under pressure and changes to it gaseous state when the liquid is dispensed into a lower pressure ambient environment, such as when the liquid components exit the gun and enter the nozzle. 
         [0007]    While polyurethane foam is well known, the formulation varies considerably depending on application. In particular, while the polyols and isocyanates are typically kept separate in the “B” and “A” containers, other chemicals in the formulation may be placed in either container with the result that the weight or viscosity of the liquids in each container varies as well as the ratios at which the “A” and “B” components are to be mixed. In dispensing gun applications which relate to this invention, the “A” and “B” formulations are such that the mixing ratios are generally kept equal so that the “A” and “B” containers are the same size. However, the weight, more importantly the viscosity, of the liquids in the containers invariably vary from one another. To adjust for viscosity variation between “A” and “B” chemical formulations, the “A” and “B” containers are charged (typically with an inert gas) at different pressures to achieve equal flow rates. The metering valves in a two-component gun, therefore, have to meter different liquids at different pressures at a precise ratio under varying flow rates. For this reason (among others), some dispensing guns have a design where each metering rod/valve is separately adjustable against a separate spring to compensate not only for ratio variations in different formulations but also viscosity variations between the components. The typical two-component dispensing gun in use today can be viewed as two separate one-component dispensing guns in a common housing discharging their components into a mixing chamber or nozzle. This practice, typically leads to operator errors. To counteract this adverse result, the ratio adjustment then has to be “hidden” within the gun, or the design has to be such that the ratio setting is “fixed” in the gun for specific formulations. The gun cost is increased in either event and “fixing” the ratio setting to a specific formulation prevents interchangeability of the dispensing gun. 
         [0008]    In addition to the ratio control which distinguishes two-component dispensing guns from one-component dispensing guns, a concern which affects all two-component gun designs (not present in one-component dispensing guns) is known in the trade as “cross-over”. Generally, “cross-over” means that one of the components of the foam (“A” or “B”) has crossed over into the dispensing mechanism in the dispensing gun for the other component (“B” or “A”). Cross-over may occur when the pressure variation between the “A” and “B” cylinders becomes significant. This may occur when the foam formulation initially calls for the “A” and “B” containers to be at high differential charge pressures and the containers have discharged a majority of their components. As known in the art, containers are accumulators which inherently vary the pressure as the contents of the container are used. To overcome this problem, it is known to equip the guns with conventional one-way valves, such as a poppet valve. While necessary, the dispensing gun&#39;s cost is increased. 
         [0009]    Somewhat related to cross-over and affecting the operation of a two-component gun is the design of the nozzle. The nozzle is typically a throw away item detachably mounted to the nose of the gun. Nozzle design is important for cross-over and metering considerations in that the nozzle directs the “A” and “B” components to a static mixer within the tip. For example, one gun completely divides the nozzle into two passages by a wall extending from the nozzle nose to the mixer. The wall lessens but does not eliminate the risk of cross-over since the higher pressurized component must travel into the mixer and back to the lower pressure metering valve before cross-over can occur. 
         [0010]    A still further characteristic distinguishing two-component from one-component gun designs resides in the clogging tendencies of two-component guns. Because the foam foaming reaction commences when the “A” and “B” components contact one another, it is clear that, once the gun is used, the static mixer will clog with polyurethane foam or froth formed within the mixer. This is why the nozzles, which contain the static mixer, are designed as throw away items. In practice, the foam does not instantaneously form within the nozzle upon cessation of metering to the point where the nozzles have to be discarded. Some time must elapse. This is a function of the formulation itself, the design of the static mixer and, all things being equal, the design of the nozzle. 
         [0011]    The dispensing gun of the present invention is particularly suited for use in two-component polyurethane foam “kits” typically sold to the building or construction trade. Typically, the kit contains two pressurized “A” and “B” cylinders (150-250 psi), a pair of hoses for connection to the cylinders and a dispensing gun, all of which are packaged in a container constructed to house and carry the components to the site where the foam is to be applied. When the chemicals in the “A” and “B” containers are depleted, the kit is sometimes discarded or the containers can be recycled. The dispensing gun may or may not be replaced. Since the dispensing gun is included in the kit, kit cost considerations dictate that the dispensing gun be relatively inexpensive. Typically, the dispensing gun is made from plastic with minimal usage of machined parts. 
         [0012]    The dispensing guns cited and to which this invention relates are additionally characterized and distinguished from other types of multi-component dispensing guns in that they are “airless” and do not contain provisions for cleaning the gun. That is, a number of dispensing or metering guns or apparatus, particularly those used in high volume foam applications, are equipped or provided with a means or mechanism to introduce air or a solvent for cleaning or clearing the passages in the gun. The use of the term “airless” as used in this patent and the claims hereof means that the dispensing apparatus is not provided with an external, cleaning or purging mechanism. 
         [0013]    While the two-component dispensing guns discussed above function in a commercially acceptable manner, it is becoming increasingly clear as the number of in situ applications for polyurethane foam increase, that the range or the ability of the dispensing gun to function for all such applications has to be improved. As a general example, the valves or connectors that limit the amount of cross-over that occurs need to be efficient in order to prevent any cross-over from occurring between materials “A” and “B”. 
         [0014]    Further limitations and disadvantages of conventional, traditional, and proposed approaches will become apparent to one of skill in the art, through comparison of such systems and methods with certain embodiments the claimed invention as set forth in the remainder of the present application with reference to the drawings. 
       SUMMARY OF THE INVENTION 
       [0015]    In one embodiment of the invention a variably tensionable check valve with a first end and a second end that includes a housing, a tension adjuster, a resiliently deformable elastic member, and a flow restriction member biased in a closed position. The housing includes a first portion, a second portion, and first and second passageways with a transition portion therebetween. The second portion includes at least one peripherally extending raised rib and a second internal passageway. The surface area of a cross-section of the first internal passageway is greater than the surface area of a cross-section of the second internal passageway. The tension adjuster, the elastic member, and the flow restriction member are located within the first internal passageway. The tension adjuster secures the elastic member and the flow restriction member within the first internal passageway, and the rotational movement of the tension adjuster modifies the biasing force of the elastic member. 
         [0016]    In another embodiment of the invention the variably tensionable check valve includes first and second ends inside a housing, with hex jam screw, spring, and metallic sphere biased in a closed position. The housing includes first and second portions. The first portion includes a first external sealing surface that provides a leak-proof connection with a dispensing gun, a second external sealing surface capable of securing the check valve to said dispensing gun, a transition portion, and a substantially cylindrical first internal passageway. The first internal passageway includes a threaded surface and a smooth surface. The transition portion forms a pair of tangential planes forming an angle of about ninety degrees. The second portion includes a third external sealing surface and a substantially cylindrical second internal passageway. The diameter of the smooth surface of the first internal passageway is greater than the diameter of the second internal passageway. The transition portion is also interposed between the first internal passageway and the second internal passageway. The hex jam screw, the spring, and the metallic sphere are located within the internal passageway. The hex jam screw secures the spring and the metallic sphere within the first internal passageway. Rotational movement of the hex jam screw modifies the biasing force of the spring. 
         [0017]    In yet another embodiment of the invention the variably tensionable check valve includes first and second ends inside a housing, with tension adjuster, resiliently deformable elastic member, and flow restriction member biased in a closed position. The housing includes a first portion and a second portion. The first portion includes means for sealing the check valve to a dispensing gun, means for securing the check valve to the dispensing gun, a transition portion, and a first internal passageway. The first internal passageway includes means for securing the tension adjuster. Second portion includes means for securing the check valve to a hose and a second internal passageway. The surface area of a cross-section of the first internal passageway is greater than the surface area of a cross-section of the second internal passageway. The transition portion is interposed between the first internal passageway and the second internal passageway. The tension adjuster, the elastic member, and the flow restriction member are located within the first passageway. The tension adjuster also secures the elastic member and the flow restriction member within the first passageway. 
         [0018]    These and other advantages and novel features of the claimed invention, as well as details of illustrated embodiments thereof, will be more fully understood from the following description and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  illustrates a rear perspective view of a dispensing gun that may utilize an embodiment of the invention; 
           [0020]      FIG. 2  illustrates a front perspective view of  FIG. 1 ; 
           [0021]      FIG. 3  illustrates a side elevational view of a cutaway of  FIG. 1 ; 
           [0022]      FIG. 4  illustrates a top elevational view of a cutaway of  FIG. 1 ; 
           [0023]      FIG. 5  illustrates an enlarged assembly view in partial cross-sectional view of an embodiment of the invention; 
           [0024]      FIG. 6  illustrates an enlarged cross-sectional view of  FIG. 5  in a first closed position; 
           [0025]      FIG. 7  illustrates an enlarged cross-sectional view of  FIG. 5  in a second open position; 
           [0026]      FIG. 8  illustrates an enlarged cross-sectional view of another embodiment of the invention; 
           [0027]      FIG. 9  illustrates an enlarged cross-sectional view of another embodiment of the invention; 
           [0028]      FIG. 10  illustrates an enlarged cross-sectional view of another embodiment of the invention; 
           [0029]      FIG. 11  illustrates a side elevational view in partial cross-sectional view of a dispensing gun utilizing a variably adjustable adapter; and 
           [0030]      FIG. 12  illustrates a perspective view of a dispensing gun utilizing a variably adjustable adapter, a pair of hoses, and a pair of portable containers. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    The best mode for carrying out the invention will now be described for the purposes of illustrating the best mode known to the applicant at the time of the filing of this application. The examples are illustrative only and not meant to limit the invention, as measured by the scope and spirit of the claims. 
         [0032]      FIGS. 1 and 2  illustrate an airless two-component dispensing gun  10 . Dispensing gun  10  may be viewed as comprising a one-piece gun body  12  (which includes components to be described) with a detachably secured disposable nozzle  13 . In one preferred embodiment, the gun is molded from polypropylene and the nozzle is molded from an ABS (Acrylonitrile-Butadiene-Styrene) plastic. While one of the objects of the invention is to provide an inexpensive dispensing gun achieved in part by the molding gun body  12  and nozzle  13  from plastic, the invention in its broader sense is not limited to a dispensing gun molded from any particular plastic and in a broader sense, includes metallic dispensing guns and/or dispensing guns with some metallic components. 
         [0033]    Gun body  12  may be further defined as having integral portions including a longitudinally-extending valve portion  15  to which nozzle  13  is releasably connected and terminating at a longitudinally-extending trigger portion  16 , in turn, terminating at longitudinally-extending spring portion  17  from which transversely extends handle portion  18 . Within gun body housing  12  is a pair of hose openings  22 ,  23 , canted as shown, to which the “A” and “B” hoses (not shown) are attached, respectively, by conventional quick connect couplings or other retaining mechanisms (e.g., friction fitting O-rings). Dispensing gun  10  is also provided with pivotable trigger  20  extending within trigger body portion  16 . It should be appreciated that when the operator grasps dispensing gun  10  about handle  18  for finger actuation of trigger  20 , that the position of hose openings  22 ,  23  is such that the kit hoses will drape over the operator&#39;s forearm which is preferred over other conventional hose attachment positions on the dispensing gun. For example, if the hose connections were attached to the handle bottom, it is possible for the hoses to become entangled with the operator&#39;s feet. If the hoses are attached to the rear end of the gun, the hoses rest on the operator&#39;s wrist. If the hoses are conventionally attached to the top of the gun, they can drape on either side of the gun and distort the pistol feel of the gun. Canting hose openings  22 ,  23  is thus believed to provide some ergonomic benefit while contributing to the improved performance of dispensing gun  10  as described below. 
         [0034]    Referring now to  FIGS. 3 and 4 , dispensing gun  10  is shown in vertical and horizontal cross-section views, respectively, to best illustrate the overall relationship of the gun components. In gun body valve portion  15 , there is formed a pair of parallel, open ended, laterally displaced and straight dispensing passages  25 ,  26  which are identical to one another so that a description of one dispensing passage such as a dispensing passage  25  for component “A” will apply to the other dispensing passage  26 . Within each dispensing passage is placed a longitudinally-extending metering rod  28  and the metering rod for dispensing the “A” component in passage  25  is not shown in  FIG. 4  for drawing clarity. Metering rod  28  will be defined in further detail below but generally has tip section  29  at one end terminating in intermediate sealing section  30 , in turn, terminating at yoke collar section  31  at the opposite end of metering rod  28 . Metering rod sections  29 ,  30  and  31  are cylindrical in one preferred embodiment but conceptually could be tubular. Each metering rod  28  has a pair of grooves  33  for an O-ring seal (not shown) to prevent the liquid component in dispensing passage  25  or  26  from escaping out an end opening  34  in each dispensing passage  25 ,  26  through which intermediate sealing section  30  extends. The opposite end opening of each dispensing passage  25 ,  26  is formed as an especially configured valve seat  35  which will be explained in further detail below. 
         [0035]    For consistency in terminology, when describing dispensing gun  10 , “longitudinal” will refer to the direction of the dispensing gun along the long axis of dispensing passage  25 ,  26  or metering rods  28 , i.e., x-x plane; “transverse” will refer to the direction of the gun along the long axis of handle portion  18 , i.e., z-z plane; and, “laterally” will refer to the direction of the gun such as the distance spanning the spacing between dispensing passages  25 ,  26 , i.e., the y-y plane. 
         [0036]    Within valve body portion  15  are two laterally spaced and essentially straight feed passages  37  in fluid communication at one end with hose opening  22  or  23  and at the opposite end with dispensing passage  25  or  26  at a position in a dispensing passage adjacent valve seat  35 . Feed passage  37  extends along axis  38  which forms an acute angle of about twenty (20) degrees with dispensing passage  25  or  26 , preferably extending not greater than about thirty (30) degrees. The geometric arrangement of a longitudinally-extending dispensing passage through which a sealed metering rod extends with a feed passage in between the metering tip of the metering rod and the rod seal is somewhat similar to conventional arrangements used in one-component dispensing guns. However, the one-component guns introduce the one-component foam at a position spaced from the dispensing passage&#39;s valve seat and form angles with the feed passages larger than the acute angle of the present invention. Based on a review of existing two-component gun designs, it was concluded that improved metering of the dispensing gun is achieved if turbulent flow of the “A” and “B” components through the dispensing gun can be alleviated or minimized. Simply put, if abrupt changes in flow direction of the liquid foam components within the gun are avoided, improved gun operation will result. The arrangement of feed passages  37 , dispensing passages  25 ,  26  and metering rods  28  is believed to alleviate or reduce turbulent flow of the liquid components through dispensing gun  10 . 
         [0037]    Referring still to  FIGS. 3 and 4 , trigger  20  has yoke crossbar portion  40  with a pair of elongated metering rod openings  41  formed therein through which intermediate sealing section  30  of each metering rod extends. Extending transversely from yoke crossbar portion  40  of trigger  20  in the direction of handle  18  is recessed trigger lever  44 . Transversely extending from the opposite side of yoke crossbar portion  40  is rounded trigger pivot portion  45 . Trigger pivot portion  45  fits within U-shaped trigger recess  47  formed within trigger body portion  16 . Trigger pivot portion  45  is not pinned or journaled within U-shaped recess  47  and can be viewed as floating. Movement of trigger lever  44  causes trigger pivot  45  to pivot within trigger recess  47  moving yoke crossbar  40  into contact with yoke collar section  31  of each metering rod  28  in a manner which causes metering of the “A” and “B” liquid components. 
         [0038]    Within spring body portion  17  of dispensing gun  10 , is positioned single spring  50 . Spring  50  is compressed between inner spring retainer  51  and outer spring retainer  52  which perhaps, as best shown in  FIG. 4 , has a bayonet clip which snaps into openings in spring body portion  17 . Inner spring retainer  51  has a pair of tubular projections  53  extending therefrom which fit within openings formed in the rear surface of yoke collar section  31 . The design of inner spring retainer  51  thus provides a form of alignment assuring equal travel of each metering rod  28  in dispensing passages  25 ,  26 . In conventional, two-component dispensing guns in commercial use, separate springs are provided for each metering rod (perhaps to provide different spring forces for each metering rod). As noted in the Background, the polyurethane foam or froth components under discussion are formulated to provide equal ratios of the “A” and “B” components. When separate springs are used, it is possible for one spring to set when compared to the other spring, tending to result in an off-ratio dispensing gun. Two-component dispensing gun  10  of the present invention avoids this concern by using a single spring in combination with inner spring retainer  51  and yoke crossbar  40  of trigger  20  to assure that movement of trigger  20  will result in equal movement of both metering rods  28  in dispensing passages  25 ,  26 . Equal ratio metering is mechanically forced and the single spring  50  exerts a constant force on both metering rods  28  so that binding within metering rod openings  41  of trigger crossbar portion  40  does not occur. 
         [0039]      FIG. 5  is an assembly view, while  FIGS. 6 and 7  are cross-sectional views shown in partial cross-section. Hose barb check valve  60  includes tension adjuster  62 , resilient elastic member  66 , flow restriction member  68 , and housing  70 . Check valve  60  is assembled by inserting flow restriction member  68  into first passageway  82  of check valve  60 , followed by insertion of resilient elastic member  66  into first passageway  82 , and lastly, by securing tension adjuster  62  to first end  92  of first passageway  82 . When trigger  20  moves towards handle  18 , cylinder pressure associated with material “A” and “B” overcomes the inherent biasing force associated with reversibly resilient member  68 , thereby allowing materials “A” and “B” to flow from second end  94  to first end  92  substantially unrestricted. The flow of materials “A” or “B” forces flow restriction member  68  towards tension adjuster  62 . As flow restriction member  68  is forced toward tension adjuster  62 , elastic member  66  will compress, thereby allowing materials “A” or “B” to flow from second end  94  to first end  92 . When trigger  20  moves away from handle  18 , cylinder pressure associated with materials “A” and “B” are then overcome by the inherent biasing force associated with reversibly resilient member  68 , thereby decompressing elastic member  66 , which then forces flow restriction member  68  to engage transition portion  88 . 
         [0040]    Housing  70  may be made of a metal, such as iron, steel, lead, aluminum, or tin, or with a hard plastic, such as a polycarbonate. Housing  70  further includes first portion  72  and second portion  78 , wherein the innermost diameter of second portion  78  is less than the innermost diameter of first portion  72 . Second portion  78  is substantially cylindrical in shape, with a “serrated” exterior peripheral surface  80  on the outermost region of second portion  78  in order to increase and facilitate leak-proof connection with hose  100 , as shown in  FIG. 12 . The number of peripherally extending raised ribs or serrations  80  are at least one and preferably two or more. Second portion  78  also includes a second passageway  90  that is located in the interior region of second portion  78 .  FIG. 5  illustrates second passageway  90  as being cylindrical in shape, however, other volumetric shapes may be utilized such as a hollow rectangular solid. The internal diameter of second passageway  90  is preferably less than the diameter of a surface of the outermost region of second portion  78 , which includes surfaces of serration  80 . Moreover, the outermost diameter of first portion  72  is less than the diameter of hose openings  22 ,  23  so that housing  70  may be inserted into hose openings  22 ,  23 . Housing  70  may also be a monolithic, in that it is constructed from one continuous piece of material. 
         [0041]    With continued reference to  FIGS. 5 through 7 , first portion  72  includes at least one sealing portion  74 , securing portion  76 , and first passageway  82 . Sealing portion  74  and securing portion  76  are open channels that encircle outer peripheral surface of first portion  72 . Sealing portion  74  and securing portion  76  are shown as square or rectangular channels, however, the channels may also have other cross-sectional shapes, as shown in  FIGS. 8 through 10 , which are more oval or circular in nature. FIGS.  5  through  7  also show check valve  60  as having two sealing portions  74 , however, only one is required. A resiliently deformable sealant, such as a rubber O-ring (not shown), may be positioned about sealing portion  74  in order for the engagement between the surface of hose openings  22 ,  23  and check valve  60  to have a more leak-proof connection. A secure connection between check valve  60  and dispensing gun  10  enable all of material “A” and “B” to flow through check valve  60  and be dispensed as a combined material. Additionally, securing portion  76  is capable of accepting a fastener (not shown), such as a cylindrical or rectangular shaped rod, in order to fasten check valve  60  to dispensing gun  10  after check valve  60  has been inserted into hose openings  22 ,  23 . Securing portion  76  also prevents check valve  60  from detaching from dispensing gun  10  during operation. If materials “A” and “B” were hazardous materials, it would be detrimental to the user if hose  100  detached from dispensing gun  10  during its operation. 
         [0042]    The inner surface of first passageway  82  may include an externally-threaded surface  84  and an exterior smooth surface  86 . Continuing with  FIGS. 5 through 7 , threaded surface  84  extends from first end  92  to smooth surface  86 , and is capable of retaining tension adjuster  62 , completely or marginally by mating exterior and interior threaded surfaces. Tension adjuster  62  is a retainer that may be a screw with a threaded outer surface and interior opening  64 . Interior opening  64  of tension adjuster  62  may be in the shape of a polygon, such as a triangle, quadrilateral, pentagon, hexagon, heptagon, octagon, or any other shape that may be realized by one of ordinary skill in the art to rotate tension adjuster  62 . An example of a screw with a hexagon-shaped interior opening  64  and threaded exteriorly is a hex jam screw. As tension adjuster  62  turns clockwise, which conventionally “tightens” an object, tension adjuster  62  moves closer to flow restriction member  68 , thereby compressing elastic member  66  and increasing the associated internal biasing force of check valve  60 . 
         [0043]    Furthermore, the cross-sectional area of flow restriction member  68  is larger than the cross-sectional area of second passageway  90 , thereby impeding any material from flowing between first passageway  82  and second passageway  90 . If first passageway  82  and second passageway  90  are cylindrical in shape, the diameter of first passageway  82  is larger than the diameter of second passageway  90 . The region between first passageway  82  and second passageway  90  is transition portion  88 , which is the transitional region between the outer surface of first passageway  82  and second passageway  90 . Transition portion  88  may be a linear slope, as shown in  FIGS. 5 and 7  through  9 , a curve, as shown in  FIG. 10 , or perpendicular to first passageway  82  and second passageway  90  (not shown). If transition portion  88  is a slope, a pair of tangential planes extending from the corresponding slopes form an angle of about ninety (90) degrees, as shown in  FIG. 8  by transition angle  96 , which is a vertically opposite angle to the angle created by the pair of tangential planes. Transition angle  96  may also be an angle less than ninety (90) degrees, as shown in  FIG. 9 . If transition portion  88  is a curve, as in  FIG. 10 , the curvature is a tangential portion of the circumference of a circle, which has a corresponding radius, an ellipse, or parabola. The curvature may also be an inverse-tangential portion of the circumstance of a circle, which has a corresponding radius, an ellipse, or parabola, similar to the corresponding tangential portion of flow restriction member  68 , as shown in  FIG. 6 . This allows flow restriction member  68  to “sit” in transition portion  88  to provide as much contacted surface area as possible, which then provides greater sealing capabilities. 
         [0044]      FIG. 11  illustrates a side elevational view of dispensing gun  10  utilizing check valve  60 . Check valve  60  is inserted into hose openings  22 ,  23 , thereby linking hose  100  to dispensing gun  10 . Hose  100  may further be secured to check valve  60  by utilizing a hose clamp (not shown).  FIG. 12  illustrates a perspective view of dispensing gun  10  utilizing check valve  60 , pair of hoses  100 , and pair of portable containers  98 . 
         [0045]    While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.