Patent Abstract:
A coupling device for fueling automobile gasoline tanks is disclosed and claimed. The coupling has two parts: a cap assembly (female half) and a nozzle assembly (male half). Little or no spillage occurs due to opposing flush faces of the female main valve and the plug of the male. The cap assembly is affixed to an existing gasoline tank (fuel storage tank) or alternatively can be supplied as original equipment on a new automobile. Fuel vapor is extracted from the automobile fuel tank with high efficiency and returned to the pumping station for storage and/or reprocessing. Vapors and/or liquid fuel are extracted through the portion of the gasoline tank cap assembly which resides within the tank. Apertures in the cap assembly communicate with an annular passageway which removes the vapors to ports which mate with peripheral apertures in a concentric nozzle having an outer sheath and an inner fluid conduit. The gasoline tank cap assembly includes a vent valve for relieving pressure within the tank when necessary. A vent sleeve is also provided for supplying air to the gasoline tank when necessary. A method of recovering fuel vapor from a fuel storage tank is also disclosed and claimed.

Full Description:
FIELD OF THE INVENTION  
         [0001]    As liquid fuel enters a vehicle gasoline tank during fueling, fuel vapors are displaced out of the tank and into the atmosphere. This invention relates to a coupling which includes a cap assembly (female coupling half) which sealingly engages a standard vehicle gasoline tank and a nozzle assembly (male coupling half) which is attached to or is integral with the spout of a hand-held fuel dispensing nozzle. The cap assembly may be adapted to any existing vehicle gasoline tank or it may be installed without an adapter as an integral part of a vehicle gasoline tank.  
           [0002]    The nozzle assembly on the spout of the dispensing nozzle couples with the cap assembly of the vehicle gas tank during fueling and provides for fuel vapor recovery directly from the vehicle gasoline tank to the vacuum recovery system. A predetermined pressure differential between the vehicle gasoline tank and the atmosphere is maintained by a vent valve and a vent sleeve in the cap assembly.  
         BACKGROUND OF THE INVENTION  
         [0003]    It is highly desirable to recover fuel vapor during refueling of a vehicle gasoline tank. Damage to the environment caused by vapor escape to the environment is well documented in U.S. Pat. No. 5,327,943 to Strock et al. issued Jul. 12, 1994. Hydrocarbon vapor release to the atmosphere when exposed to sunlight can react with air contaminants to create ozone.  
           [0004]    Fuel costs continue to soar and the present crude oil price exceeds $30.00 per barrel thus making vapor recovery economical. U.S. Pat. No. 4,429,725 to Walker et al. cites a 97.6% recovery of the vapor which would have been emitted (without vapor recovery) but for the use of the &#39;725 invention.  
           [0005]    U.S. Pat. Nos. 5,385,178 and 5,295,521 to Bedi disclose a flat planar surface disposed on a filler cap with the cap being threaded into an existing gasoline tank receptacle. Bedi &#39;178 and &#39;521 further disclose two commercially available coupling halves mounted into or on the flat planar surface. The couplings halves mate with commercially available reciprocal coupling halves. One coupling feeds and is connected to a fuel vapor return line and the other coupling feeds and is connected to fuel a supply line. The vapor return line is separate from and independent of the fuel dispensing nozzle.  
           [0006]    There are two known vapor recovery systems: balanced pressure systems and vacuum assist systems. Balanced pressure systems use an elastomeric boot or other positive sealing device to engage and seal the fill opening of the tank during refueling. “The interior of the boot is connected to a vapor return conduit to the underground storage tank so that hydrocarbon vapors emitted during fueling naturally flow to the storage tank to maintain the pressure balance between the vehicle tank and the storage tank. The vacuum assist differs from the balanced pressure system because it does not require a tight sealing boot or some other positive sealing arrangement with the fill opening or filler pipe of the vehicle tank. Instead, the vapor return conduits are connected through a vapor pump or other vacuum inducing assist device to collect and transport the vapors emitted during fueling to the storage tanks.” See, the &#39;943 patent to Strock et al. at column 1, lines  51 - 69 .  
           [0007]    Given the high cost of fuel and given the environmental damage caused by fuel vapor in the atmosphere, it is highly desirable to increase the efficiency of the vapor recovery process. An increase in the efficiency of the vapor recovery process will produce a better environment with attendant financial savings. The coupling of the instant invention combines the features of positive sealing and vacuum assist. The nozzle assembly seals against the cap assembly. Passageways in the cap and nozzle assemblies permit fluid and gaseous communication between the vehicle tank and the service station storage tank.  
           [0008]    The invention will be better understood when reference is made to the Summary of the Invention, Brief Description of the Drawings, Description of the Invention and Claims which follow below.  
         SUMMARY OF THE INVENTION  
         [0009]    A coupling for a fuel storage tank such as a vehicle gasoline tank is disclosed and claimed. The coupling includes a cap assembly (female coupling half) and a nozzle assembly (male coupling half). The cap assembly is sealingly attached to the vehicle gasoline tank and the nozzle assembly is affixed to the spout of a dispensing nozzle. Once attached to an existing gasoline tank the female coupling half (cap assembly) is normally not removed except if maintenance is to be performed. Additionally, the female coupling half (cap assembly) may be removed from the vehicle gasoline tank if the vehicle is being fueled at a nonconforming service station (i.e., one which does not employ the nozzle assembly of the instant invention. The cap assembly includes a body and the body includes a plurality of apertures in communication with the vehicle gasoline tank. A passageway interconnects the plurality of apertures with a plurality of ports. A substantially flush faced valve covers and closes the ports when the cap assembly is not coupled to the nozzle assembly. The valve uncovers and opens the ports when the coupling halves, namely, the cap assembly and the nozzle assembly are coupled together.  
           [0010]    The nozzle assembly includes an annular passageway formed by an outer sheath which is concentric with an inner fluid conduit. The nozzle assembly includes a plug mounted and secured partially in the annulus having radial ports therein. A flush faced valve is formed by the plug having ports and a sliding sleeve. The spout of a dispensing nozzle is generally the portion of the nozzle which is distal (remote) from the hand-held portion of the nozzle. Apertures in the outer sheath enable communication between the vehicle fuel tank and the passageway of the nozzle assembly when the coupling halves are coupled together. The passageway of the cap assembly communicates with the vehicle gas tank via apertures. Ports of the cap assembly communicate with the passageway of the cap assembly and with the nozzle assembly via the apertures in the outer sheath of the nozzle assembly when the coupling halves are coupled together.  
           [0011]    When the male coupling half (nozzle assembly) and the female coupling half (cap assembly) are uncoupled little or no spillage occurs due to the flush face configuration of the valve in the female half and the flush face configuration of the plug in the male half.  
           [0012]    Vapor from a vehicle gasoline tank is displaced during fueling of the vehicle as the volume for the vapor is reduced by incoming fuel. Use of the term “fueling” herein includes the term “refueling.” When vapor is displaced it is directly communicated to a vacuum assisted recovery system. Seals insure that the vapor remains in the passageway of the coupling halves and does not migrate to the atmosphere. Seals also insure that the liquid gasoline is delivered to the vehicle gasoline tank without fluid or vapor migration to the atmosphere.  
           [0013]    When the halves are coupled together vapor recovery is effected utilizing mechanical seals and passageways under the influence of a vacuum. When the halves are uncoupled the cap assembly functions to relieve excess pressure within the vehicle gasoline tank. As liquid gasoline is consumed a vacuum is created within the tank and the cap assembly also functions to add air from the atmosphere into the tank.  
           [0014]    It is an object of the present invention to provide a coupling for a vehicle gasoline tank and gasoline dispensing nozzle which maximizes vapor recover from the vehicle gasoline tank.  
           [0015]    It is a further object of the present invention to provide a cap assembly which sealingly interconnects with a vehicle gasoline tank.  
           [0016]    It is a further object of the present invention to provide a cap assembly which includes an adapter enabling interconnection with existing vehicle gasoline tanks.  
           [0017]    It is a further object of the present invention to provide a cap assembly which includes a vent valve for relieving pressure when a curtain pressure differential between the interior of a vehicle gasoline tank and the atmosphere is exceeded.  
           [0018]    It is a further object of the present invention to provide a cap assembly which includes a vent sleeve for admitting air to the interior of a vehicle gasoline tank when a curtain pressure differential between the atmosphere and the interior of the gasoline tank is exceeded.  
           [0019]    It is a further object of the present invention to provide a cap assembly which is small enough to fit within the gasoline cap access door and the vehicle gasoline tank.  
           [0020]    It is a further object of the present invention to provide a nozzle assembly affixed to the spout of a dispensing nozzle.  
           [0021]    It is a further object of the present invention to provide a low or no spill fuel coupling.  
           [0022]    It is a further object of the present invention to provide a cap assembly for the removal of gasoline or other fuel vapor directly from a fuel storage tank through apertures in the cap assembly which interconnect with an annular passageway which, in turn, interconnects with ports.  
           [0023]    It is a further object of the present invention to provide a cap assembly which includes a main valve for covering and uncovering ports which interconnect with an annular passageway.  
           [0024]    It is a further object of the present invention to provide a cap assembly, or female coupling half, which sealingly couples together with a nozzle assembly, or male coupling half.  
           [0025]    It is a further object of the present invention to provide a cap assembly which sealingly couples with a nozzle assembly and which further includes a sealed passageway interconnecting the vehicle gasoline tank and a vacuum source interconnected with a passageway in the nozzle assembly.  
           [0026]    It is a further object of the present invention to provide a female coupling half and a male coupling half adapted to interconnect with a vehicle gasoline tank.  
           [0027]    It is a further object of the present invention to provide a nozzle assembly which includes a plug having ports for the delivery of liquid when coupled with the cap assembly. The plug is partially press fit into an annular space defined by the inner fluid conduit and the outer sheath of the nozzle assembly.  
           [0028]    It is a further object of the present invention to provide a nozzle assembly which has an inner fluid conduit, an outer sheath having a plurality of apertures therein, a plug partially press fit within and tack welded to the fluid conduit and outer sheath, a sliding sleeve affixed to a sleeve guide, and a body.  
           [0029]    The invention will be better understood when reference is made to the Brief Description of the Drawings, Description of the Invention and Claims which follow hereinbelow. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0030]    [0030]FIG. 1 is a front elevational view of the cap assembly (female coupling half).  
         [0031]    [0031]FIG. 2 is a front elevational view of another embodiment of the cap assembly illustrating a locking protrusion.  
         [0032]    [0032]FIG. 2A is a top view of the cap assembly of FIG. 2.  
         [0033]    [0033]FIG. 3 is a front elevational view of the nozzle assembly (male coupling half).  
         [0034]    [0034]FIG. 4 is a front elevational view of the cap assembly coupled together with the nozzle assembly.  
         [0035]    [0035]FIG. 5 is a cross-sectional view of the cap assembly (female coupling half) of FIG. 1.  
         [0036]    [0036]FIG. 5A is an enlarged portion of FIG. 5 illustrating the valves.  
         [0037]    [0037]FIG. 6 is a cross-sectional view of the nozzle assembly of FIG. 3.  
         [0038]    [0038]FIG. 6A is a cross-sectional view of the nozzle assembly shown with a sensing conduit in the annulus formed by the outer sheath and the inner fluid conduit.  
         [0039]    [0039]FIG. 6B is an enlarged portion of FIG. 6A.  
         [0040]    [0040]FIG. 7 is a cross-sectional view of the cap assembly coupled together with the nozzle assembly.  
         [0041]    [0041]FIG. 7A is an enlarged portion of the cap assembly illustrated in FIG. 7.  
         [0042]    [0042]FIG. 8 is a cross-sectional view of another embodiment of the invention for use with an original equipment vehicle gasoline tank.  
         [0043]    [0043]FIG. 9 is a front elevational view of a typical gasoline tank fuel connection with the vehicle&#39;s gas cap removed.  
         [0044]    [0044]FIG. 10 is a schematic diagram illustrating the method of utilizing the coupling with an existing gasoline tank.  
         [0045]    A better understanding of the drawings will be had when reference is made to the Description of the Invention and Claims which follow hereinbelow. 
     
    
     DESCRIPTION OF THE INVENTION  
       [0046]    [0046]FIG. 7 is a cross-section of the cap assembly  100  coupled together with the nozzle assembly  300 . The cap assembly  100  is sometimes referred to herein as the female coupling half and the nozzle assembly  300  is sometimes referred to herein as the male coupling half. The nozzle assembly or male coupling half  300  is affixed to the spout portion  704  of a fuel dispensing nozzle (not shown). Fuel dispensing nozzles are well known and one such fuel dispensing nozzle is illustrated in U.S. Pat. No. 4,429,725 to Walker et al. issued Feb. 7, 1984. The nozzle assembly includes an outer sheath  604  and an inner fluid conduit  603  as viewed in FIG. 7. The outer sheath  604  is concentric with the inner fluid conduit  603  and includes apertures  606  therein. Apertures  606  are viewed in FIG. 7 as well as in FIG. 6. Generally, apertures  606  are circumferentially spaced in the outer sheath in two rows. Annulus  605  is formed between the inner conduit  603  sometimes referred to as the fluid conduit  603  and the outer sheath  604 . See, FIG. 6.  
         [0047]    Still referring to FIG. 6, plug  601  is generally cylindrically shaped and includes a diametrically reduced section  602  which is press fit into annulus  605 . The press fit is indicated by reference numeral  614  as indicated in FIG. 6. Additionally, plug  601  is tack welded  615  to the outer sheath  604 . Plug  601  includes flush face  305  which engages the substantially flush face of main valve  508  during coupling. When the coupling halves are uncoupled, valve  508  closes and prevents vapor and/or fluid from escaping. Similarly, when the coupling halves are uncoupled, sliding sleeve  301  closes and seals ports  612  and prevents fluid spillage from the nozzle assembly. Very low spillage occurs upon disconnection of the coupling halves because the flush face  305  of the plug  601  abuts the substantially flush face of valve  508  and little or no fluid can reside between the faces when the coupling is connected.  
         [0048]    Seal  609  is part of the male coupling half  300  also referred to as the nozzle assembly  300 . See, FIGS. 6 and 7. Seal  609  resides in an interior circumferential groove or recess in body  303 . Body  303  is secured to the outer sheath  604  by a set screw  604  and a ferrule  611 . When the nozzle assembly  300  is coupled to the cap assembly  100 , seal  609  functions as a locking seal and it interlocks with circumferential groove  526  as best viewed in FIGS. 5 and 5A. During the process of coupling some slight misalignment is allowed between the male coupling half  300  and the female coupling half  100 .  
         [0049]    [0049]FIG. 3 is a front elevational view of the nozzle assembly  300 . The nozzle assembly includes a sliding sleeve  301  which is affixed by a threaded interconnection to a guide  302 . Body  303  is secured to the outer sheath  604  by set screw  304  and the ferrule  611 .  
         [0050]    Referring again to FIG. 7, reference numeral  607  indicates the gasoline (or other fuel) flow path and reference numeral  701  is a flow arrow indicating the path of fuel flow during fueling. During fueling the liquid fuel flows through the fluid conduit  603  leftwardly when viewing FIG. 7 and proceeds through flow ports  612  in plug  601 .  
         [0051]    [0051]FIG. 7A is an enlarged portion of the cap assembly  100  illustrated in FIG. 7. Referring to FIG. 7A, liquid fuel flows through apertures  612  as indicated by a flow arrow  701  into and through chamber  703 , past main valve  508  of the cap assembly and through ports  509  of the main valve  508  and into adapter  104 .  
         [0052]    Adapter  104  is viewed in FIGS. 1 and 5. Referring to FIGS. 5 and 7A, adapter  104  is an offset flow conduit and cap  102  which is threaded to body  101  may rotate relative to the adapter  104 . Adapter  104  is retained within body  101  of the cap assembly by retaining ring  501  and spring  504 . Teflon seals  502  and  503  seal the adapter  104  so that fluid may not escape from the interior of the cap assembly  100 .  
         [0053]    Cap assembly  100  includes a single continuous thread  103  located on the cap  102  of the assembly  100 . Grips  105  on cap  102  enable the cap assembly  100  to be threadably interconnected by hand with an existing vehicle fuel tank. The cap assembly  100  may be threaded to an existing vehicle gasoline tank by simply removing the original gas cap on the tank and replacing it with the cap assembly  100  of the present invention. Cap assembly  100  is small enough to fit inside of vehicle fuel doors when the door is closed and the cap assembly is fully threaded into the receptacle of the gas tank.  
         [0054]    Adapter  104  is inserted into and through the flapper valve  905  as indicated in FIG. 9. FIG. 9 is not to scale relative to any of the other drawing figures. Adapter  104  is offset from the central axis of the cap assembly. The cap assembly is generally cylindrically shaped and it may be gripped by grips  105  and the cap assembly screwed into an existing gasoline tank threaded connection as illustrated in FIG. 9. Reference numeral  900  illustrates the typical gasoline tank connection (nozzle receptacle) on a vehicle with the gas cap removed. Front face  901  of the receptacle engages seal  525  of the cap assembly preventing vapor from escaping to the atmosphere. The initial thread (or beginning thread) is indicated by reference numeral  902  on the receptacle. Reference numeral  903  indicates the continuous thread as it extends helically inwardly toward the gas tank. Reference numeral  904  indicates guides whereby the adapter  104  is guided into the flapper valve  905 . On some automobiles, guides  904  are used to direct the spout  704  of the dispensing nozzle into flapper valve  905  of the fuel tank. Reference numeral  906  is the housing of the typical gasoline tank cap on the vehicle.  
         [0055]    Once adapter  104  is inserted into and through flapper valve  905  the helical threads  103  of the cap assembly engage the reciprocal helical threads  902 / 903  as illustrated in FIG. 9 until seal  525  on cap  102  engages the face  901  of the gas tank receptacle.  
         [0056]    Apertures  106  in the threaded portion of the cap assembly  100  (female coupling half) are illustrated in FIGS. 1, 4,  5 ,  7 , and  7 A. Apertures  106  exist in the single continuous helical thread  103 . Thread  103  mates with thread  902 / 903  but the mating of the threads does not create a seal and gasoline vapors (or other fuel vapors) from the gasoline tank enter apertures  106  as indicated on FIG. 7 and  7 A. The vapor migrates along and between the thread  103  of the cap assembly which is screwed into the mating helical thread  903  of the gas tank receptacle  900  (nozzle receptacle). Seal  525  is an elastomeric seal which abuts the front face  901  of the gasoline tank receptacle  900  preventing escape of fuel vapor to the environment. Flow arrow  702  indicates the path of the gasoline vapors. Annulus  520  is formed between generally cylindrical cap  102  and generally cylindrical body  101  of the cap assembly  100 . Passageway designs other than an annulus may be used in the cap assembly and the nozzle assembly without departing from the spirit and scope of the invention. For instance, a bore of a plurality of bores may be used as set forth in FIG. 8.  
         [0057]    Referring to FIG. 5A, a plurality of circumferentially spaced ports  521  are located in body  101  of the female coupling half  100 . Main valve  508  is generally cylindrically shaped and includes circumferentially spaced flow ports  509  therein. Spring  507  acts between valve guide  505  and valve  508  to urge valve  508  into the closed position as illustrated in FIG. 5. Valve  508  is illustrated in the open position in FIG. 7. Valve guide  505  is also generally cylindrically shaped and has four circumferential supports spaced at 90° from each other. Spring  504  is operable between adapter  104  and valve guide  105 . Spring  504  urges the valve guide  505  to its rightward most position as viewed in FIG. 5.  
         [0058]    Threads  522  indicate the interconnection between the cap  102  and the body  101 . The adapter  104  is retained within the body  101  of the cap assembly  101  by retaining ring  501  as illustrated in FIG. 5. FIG. 5A is an enlarged portion of FIG. 5 and illustrates vent valve  512  and vent sleeve  510 . Vent valve  512  permits the release of pressure within the fuel storage tank when pressure exceeds a predetermined value. Washer  506  retains vent valve  512  and the vent sleeve  510  in position. When vapor pressure in the tank exceeds a predetermined differential between the tank and the atmosphere, pressure applied to internal face  523  of vent valve  512  urges valve  512  rightwardly against spring  513 . Spring  513  is operable between vent valve  512  and main valve  508 . When sufficient pressure is applied to face  523 , spring  513  compresses and vapor is released around seal  514 . Seal  514  is an ordinary Viton O-ring seal. Viton is a registered trademark of Dupont Dow Elastomers L.L.C. Corporation of Wilmington, Del.  
         [0059]    When fuel is used from the gas tank to fuel the automobile engine, a vacuum is created within the tank which must be relieved. To accomplish the vacuum relief, vent sleeve  510  includes an external face  524  which experiences atmospheric pressure. When the atmospheric pressure exceeds a predetermined level, spring  511  is compressed. Spring  511  is operable between valve washer  506  and vent sleeve  510 . When vent sleeve  510  is moved sufficiently leftwardly, air flows around Viton O-ring seal  515  and into the gas tank.  
         [0060]    Seals  518  and  519  are also elastomeric Viton O-ring seals and they seal circumferentially spaced ports  521  which reside in cap assembly  100 . Reference numeral  517  is also an elastomeric Viton O-ring seal which seals between cap  102  of the female coupling half and the sliding sleeve  301  of the male coupling half upon coupling. See, FIG. 7.  
         [0061]    Referring again to FIG. 7, reference numeral  702  indicates the flow path of the fuel vapor which is recovered from the fuel tank during fueling. Reference numeral  702  illustrates the path of vapor through ports  521  and apertures  606  and into the annulus  605 . Seal  613 , a Viton O-ring seal is an additional seal between the outer sheath  604  and the environment. Seals  518  and  519  are the primary seals which seal ports  521  and apertures  606  and seals  613  and  517  are backup seals. Seal  608 , a Viton O-ring seal is an additional backup seal between the sliding sleeve  301  and the outer sheath  604 . Spring  610  is operable between sliding sleeve  301  and body  303 . In FIG. 7, spring  610  is shown compressed as sliding sleeve  301  has been moved rightwardly compressing it.  
         [0062]    [0062]FIG. 4 is a front elevational view of cap assembly  100  coupled together with the nozzle assembly  300 . Reference numeral  400  illustrates the cap assembly and nozzle assembly coupled together. FIG. 2 is a front elevational view of another embodiment of the cap assembly  200  illustrating a locking protrusion  201 , a key type lock. Adapter  204  is indicated in FIG. 2.  
         [0063]    [0063]FIG. 6 is a cross-sectional of the nozzle assembly  300  illustrated in FIG. 3. FIG. 6 illustrates the nozzle assembly in the closed position with spring  610  urging sliding sleeve  301  leftwardly. FIG. 7 illustrates the open position of the nozzle or put another way, the open position of sliding sleeve  301  with respect to port  612  of the nozzle. Sleeve  301  of the nozzle assembly functions as a valve with respect to ports  612 .  
         [0064]    [0064]FIG. 8 is a cross-sectional view of another embodiment of the invention for use with an original equipment vehicle gasoline tank. Reference numeral  800  indicates the original equipment female half  800  which can be welded to a gasoline tank. Reference numeral  801  illustrates a plurality of passageways from the tank. When female half  800  is coupled together with the nozzle assembly  300  of FIG. 7, the flow arrow indicating a path of vapor flow as indicated by reference numeral  702  will be the same.  
         [0065]    [0065]FIG. 6A is a cross-sectional view of the nozzle assembly shown with the sensing conduit  616  in the annulus formed by the outer sheath  604  and the inner fluid conduit  603 . The sensing conduit  616  may be used for detecting fluid in the vapor return line. When the gas tank is full it is possible for fluid to come into apertures  106 . However, an appreciable amount of fluid is not expected in apertures  106 . FIG. 6B is an enlarged view of a portion of FIG. 6A illustrating the apertures  606  in better detail.  
         [0066]    The O-rings used in the invention are elastomeric O-rings made of Viton. The cap  102  and body  101  of the cap assembly  100  are preferably made from aluminum. Preferably the adapter seals  502 ,  503  are made of Teflon and preferably the adapter  104  is aluminum. Retaining ring  501  which retains the adapter  104  is preferably made from stainless steel. Vent valve  512  in the cap assembly  100  is preferably made of stainless steel and the vent sleeve  5120  in the cap assembly is preferably made of aluminum. The main valve  508  in the cap assembly  100  is preferably made of aluminum and the valve guide  505  is preferably made of stainless steel. In regard to the nozzle assembly  300  the sliding sleeve  301  is preferably made of stainless steel as is the sliding sleeve guide  302 . Similarly, the body of the nozzle assembly is preferably made of stainless steel.  
         [0067]    [0067]FIG. 10 is a schematic diagram  1000  illustrating the method of utilizing the coupling with an existing gasoline tank. First, the existing gas cap is removed from the existing nozzle receptacle  900  as indicated by reference numeral  1001 . The adapter  104  of the cap assembly is then inserted into and through the flapper valve  905  of the gasoline tank. See, reference numeral  1002  and FIG. 9.  
         [0068]    The cap assembly  100  is threaded into the nozzle receptacle by rotating  1003  the cap assembly with respect to the adapter thus attaching  1004  cap assembly  100  to the gasoline tank. The nozzle assembly and the cap assembly are coupled  1005  and locked  1006  together. Vapors are extracted  1007  from the gasoline tank into and through the cap and nozzle assemblies. The process of utilizing the nozzle and cap assemblies together is the same when used on a new gasoline tank except steps  1001 ,  1002 , and  1003  are not needed and the cap assembly is welded to the gasoline tank  1004 . If the cap assembly must be removed for maintenance or for use at a non-conforming service station (i.e., one that does utilize the male coupling half of the instant invention), the cap assembly is simply unscrewed from the nozzle receptacle.  
         [0069]    The instant invention has been described herein with sufficient particularity in regard to the preferred embodiments. Those skilled in the art will recognize that many changes and modifications may be made to the invention as disclosed without departing from the spirit and scope of the appended claims.

Technology Classification (CPC): 8