Abstract:
Provided are nozzles useful for controllably transferring any fluid including without limitation liquids such as hydrocarbon fuels from a first reservoir to a second reservoir. Dispensing nozzles as provided herein have several advantages, including increased control by the technician who is transferring the fluids over the nozzle itself by virtue of greater physical control and less operator fatigue. In addition, a small amount of force applied to the dispensing lever results in a relatively large opening of the control valve mechanism. Further, when line pressure is zero or near zero, it is not possible for un-metered fluid leakage to occur, which provides cost advantages to large volume vendors of liquids such as hydrocarbon fuels which are dispensed on a routine basis, such as at airports. Safety is also greatly enhanced, since latent quantities of fuel cannot flow out from lines equipped with the nozzles provided when supply lines are not pressurized.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/999,515 filed on Jul. 30, 2014, the entire contents of which are hereby incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     This invention relates generally to fluid control, and more particularly it relates to transfer and delivery of liquid substances from one location to another. 
     BACKGROUND OF THE INVENTION 
     The statements in this background section merely provide background information related to the present disclosure and may not constitute prior art. 
     Many fluids are used industrially, including water, steam, brines, oils, lubricants, motor gasolines, jet fuel, aviation fuel, diesel fuel, kerosene, heating oils, industrial chemicals, and gases. Over time in the art of transferring fluid substances, many different dispensing nozzles, valves and associated wares have been developed. These include fueling nozzles used by consumers to re-fuel automobiles, as well as similar nozzles employed on heavier equipment, aircraft refueling, etc. Of such devices available in the prior art marketplace, it is to be expected that of the delivery nozzle products offered there will be at least some disadvantages and shortcomings. 
     In the case of fueling nozzles employed in re-fueling of aircraft having a fuel tank opening located on the top of a wing of the aircraft, traditional overwing refueling requires either the re-fueling technician&#39;s elbow to be uncomfortably maintained in a position above the fueling nozzle, or for the re-fueling technician to otherwise have an awkward or uncomfortable grip on the handle of the conventional overwing fueling nozzle. In many instances, re-fueling technicians choose to climb a ladder, which inherently adds to potential hazards during an aircraft re-fueling operation. 
     Referring to the drawings, in particular  FIG. 1A , there is shown a side cutaway view of a fueling nozzle  2  of a type commonly found in the prior art, featuring a fluid entry  63 ′ at which fuel is supplied from a remote reservoir via a conduit (not shown). A technician refueling a motorized vehicle such as an aircraft typically grasps handle  6 ′ of prior art fueling nozzle  2 , places the outlet end  83  inside a fuel tank opening, and pulls dispensing lever  29 ′ with the fingers of the hand holding handle  6 ′, to dispense fuel into the fuel tank. Outlet end  83  is fitted with an annular locator flange  79  designed to keep the nozzle in a relatively stable position during the refueling operation, and a splash flange  77  to prevent fuel from spattering about during the refueling operation. Once admitted to fuel entry  63 ′, the fuel passes through handle conduit  75  and into a valve body comprising a piston  7 ′ having an interior  48 ′ slidably disposed within a bore space  51 ′. Pulling dispensing lever  29 ′ draws piston  7 ′ back towards dispensing lever  29 ′, thus opening the passageway for the fuel to continue its travel to outlet end  83  and into the receiving fuel tank. In some prior art embodiments a strainer  67 ′ is provided, as well as a ground connection point  81  for preventing the build up of static charge. In many prior art embodiments, such nozzles  2  are fitted with swivel seals  71  and a check valve  73 . In such arrangement, the pressure in the fuel supply line assists the springs  47 ′ in holding the piston  7 ′ closed, the volume behind the piston being pressurized by a small bleed hole from the main fuel supply line. These prior art devices make it very difficult for a refueling technician to pull the piston open, due to the pressure in the fuel supply line, as these prior art nozzles are designed so that the first action of the handle cracks open a plunger that relieves the pressure behind the piston, filling a cavity slowly through a bleed hole, which also empties just as quickly through the bleed hole. When the valve is closed, the interior  48 ′ of piston  7  is already filled because it is always connected to conduit  75  through a bleed hole. It is the fluid in interior  48 ′ which helps to keep piston  7  closed. The first action of the handle cracks open a plunger and relieves fluid and hence pressure from behind piston  7 . Once the pressure behind the piston is relieved, it then becomes easier to pull the handle back to move the piston out of the way, permitting fuel to flow through the nozzle, the total amount of flow being controlled by the position of the piston, which is determined by the position of the handle. In  FIG. 1B  is shown a user  70  employing a prior art fueling nozzle  2  in filling a tank  30  with a liquid fuel, wherein tank  30  is an on-board aircraft fuel tank. From  FIG. 1B  it is evident the user&#39;s elbow  36  must be elevated differently from their other limb, causing asymmetry and hence instability about their body during a re-fueling operation, in addition to stressing the muscles of the arms, shoulders and lower back, joints and musculature, which can over time lead to medical disabilities, carpal tunnel-like syndromes due to repeated asymmetrical stress. 
     SUMMARY OF THE INVENTION 
     Provided herein are devices useful for dispensing and regulating a fluid substance from a first storage reservoir to a second storage reservoir. A device according to some embodiments comprises a main housing which in some embodiments has an upper housing portion and a lower housing portion. There is a fluid inlet passage configured to be connected to a source of fluid substance from the first reservoir, present at the upper portion of the main housing. There is a fluid exit passage through which the fluid substance exits the device upon its being dispensed to its destination. A bore housing is attached to the main housing and is present between the fluid inlet passage and the fluid exit, the bore housing includes a bore. There is a central tower having a proximal end, a distal end, an outer wall, and a length dimension. The central tower is centrally-disposed on or at the bore housing at its proximal end, and the central tower further comprises a passage extending therethrough that runs parallel to its length dimension. This passage has a proximal end and a distal end. There is further at least one port passing through the outer wall, which is in fluid communication with the passage. There is a tilt valve having a head and a shank, with the shank having a first end proximal to its head, and a second end distal thereto. The head is sealingly engaged over the proximal end of the passage. There is a needle valve disposed over the distal end of the central tower, the needle valve has a length dimension that runs parallel to the length dimension of the central tower. A piston is present slidably disposed within the bore of the bore housing, the piston having a top portion and a bottom portion, and the top portion of the piston comprises an orifice centrally-located therethrough, the orifice being dimensioned sufficiently to enable the needle valve to pass therethrough. A dispensing lever is pivotally connected to the main housing, and there is an actuator lever having a first end and a second end. The first end of the actuator lever is pivotally connected to the dispensing lever, and the second end of the actuator lever is in mechanical contact with the second end of the shank of the tilt valve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings shown and described herein are provided for illustration purposes only and are merely exemplary of different embodiments provided herein, not intended to be construed in any delimitive fashion. 
         FIG. 1A  is a side cutaway view of a prior art fluid delivery control device; 
         FIG. 1B  is a perspective view of a user employing a prior art fluid delivery control device in a liquid transfer operation; 
         FIG. 2A  is a side cutaway view of a fluid delivery control device according to some embodiments of this disclosure; 
         FIG. 2B  is a perspective view of a user employing a fluid delivery control device according to some embodiments of this disclosure in a liquid transfer operation; 
         FIG. 3A  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of this disclosure; 
         FIG. 3B  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of this disclosure; 
         FIG. 4  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of this disclosure in a closed position; 
         FIG. 5  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of this disclosure in a partially-opened position; 
         FIG. 6  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of this disclosure in a fully-opened position; 
         FIG. 7  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of this disclosure in a closed position; 
         FIG. 8  is a side cutaway view of components present in a fluid delivery control device according to some embodiments of the disclosure, illustrating a check-valve subassembly. 
     
    
    
     DETAILED DESCRIPTION 
     The following description is merely exemplary in nature and is in no way intended to limit the present disclosure, application, or uses. 
     Referring now to  FIG. 2A , there is shown a side cutaway view of a fueling nozzle  10  according to some embodiments of this disclosure, configured to enable a person to dispense fuel to a fuel-receiving tank, including without limitation such tanks present on motorized vehicles, including aircraft. Fueling nozzle  10  enables its user to easily selectively commence and cease flow of a liquid fuel being charged to the vehicle&#39;s on-board fuel tank. Fueling nozzle  10  features a fluid entry  63  which is configured to receive and sealingly-engage conventional hardware disposed at a first end of a hose or other conduit, whose second end is connected to a reservoir or tank, etc. that contains a source fuel that is to be transferred to the aircraft&#39;s on-board fuel tank. 
     Fueling nozzle  10  also features a delivery end  69  at which fuel exits fueling nozzle  10  into a selected receiving tank, such as an on-board fuel tank of a motorized vehicle. During use of fueling nozzle  10 , the technician grasps handles  4 ,  6  with the right and left hands, or vice versa depending on the handedness of the individual. After insertion of delivery end  69  into a receiving tank, the technician grasps dispensing lever  29  with the fingers of the hand. To initiate the flow of fuel from conduit  65  to delivery end  69 , the technician pulls dispensing lever  29  in a direction towards the right in  FIG. 2A . 
       FIG. 2A  also shows the respective locations of various components of fueling nozzle  10 . Conduit  65  in some embodiments features a bend or angle while in other embodiments conduit  65  is linear. When bent or angled, the first and second end portions of conduit  65  are provided with swing couplings  59 ,  61  which enable 360-degree rotation of a hose or conduit attached to fueling nozzle  10  at fluid entry  63 , as well as 360-degree rotation of conduit  65  with respect to the remainder of fueling nozzle  10  at  59 . Swing couplings  59 ,  61  feature o-rings or other known, like seals to maintain a seal between ambient surroundings and the interior of conduit  65 . Thus, in a nozzle according to some embodiments the fluid inlet passage comprises a conduit that is rotatable in two dimensions. Swing couplings such as these are available from Schultz Engineered Products Inc. of Neptune, N.J. 
     In some embodiments an integral valve assembly is provided within fueling nozzle  10 , featuring upper housing  3 , lower housing  5 , piston  7 , bore housing  9 , needle valve orifice  11 , needle valve  13 , seal  17 , and tilt valve  27 . Upper housing  3  and lower housing  5  may be collectively considered as being a main housing. In some embodiments there is a fluid exit  42  passage, strainer  67 , tilt valve shank  25 , activator shaft  31  that moves axially and has an end  32 , and dispensing lever  29  having end  33 . In some embodiments strainer is shrouded by outer conduit  68 , which is a tube that also acts as a guide when inserted into the receiving bung or opening of a receiving vessel such as an on-board fuel tank. Activator shaft  31  is provided with a bushing  37  disposed thereabout, to guide activator shaft  31  and to seal the liquid/fuel passing through fueling nozzle  10  from the ambient surroundings. End  33  of dispensing lever  29  is pivotally connected at  55  to a first portion of link  35  ( FIG. 3A ), whose second portion is pivotally connected at  53  to stationary location  41  ( FIG. 3A ) present on the external portion of lower housing  5 . Such an arrangement in further combination with pivotal attachment of activator shaft  31  to dispensing lever  29  at  57 , and with the end of tilt valve shank  25  being engaged with end  32  of activator shaft  31 , provides that when such user pulls dispensing lever  29  in a direction towards the right, the sealing surface of tilt valve  27  is caused to become tilted with respect to its orientation of  FIG. 2A  and thus disengaged from, or lifted partially off of, its seat or seal  43  ( FIG. 4 ). 
     In  FIG. 2B  is shown a user  70  employing a fueling nozzle  10  according to some embodiments of this disclosure in filling a tank  30  with a liquid fuel, wherein tank  30  is an on-board aircraft fuel tank.  FIG. 2B  shows the user&#39;s hands  34  being evenly employed about fueling nozzle  10  resulting in bodily symmetry that not only eliminates bodily stresses on arms, shoulders and the lower back, joints and musculature, but also simultaneously provides for increased physical control over the fueling nozzle  10  as a whole while affording superior fluid control, by only the grasping action of the fingers on one hand. Thus, some embodiments provide for simultaneous superior physical control of the fueling nozzle  10  during a re-fueling operation with attendant reduced bodily stress, while additionally providing smoother operation and greater flow control during refueling, for reasons detailed below concerning the operation of the valving mechanism contained within fueling nozzle  10 . 
     It may appear from the drawings herein at first glance that the piston of this disclosure is disposed so that the pressure in the fuel line would push the piston open; however, this is not the case because piston  7  is an overbalanced piston, with the area on the upstream side of the piston being less than the area on the downstream side of the piston. Such feature in combination with other features as described herein including spring  47  ( FIG. 4 ) and the dimensions of elements present as a whole result in the situation that when a fueling nozzle  10  according to this disclosure is closed and the fuel supply line is pressurized, there is a greater net force on the downstream side of the piston than on the upstream side of the piston, which maintains the piston in a closed position, preventing the flow of fuel therethrough. Thus, fueling nozzle  10  effectively includes a pilot-operated control valve, having a piston whose movement regulates the amount of fuel that is able to pass through fueling nozzle  10 . The piston is to some degree spring-biased towards a closed position that blocks the flow of fuel through fueling nozzle  10  by the presence of spring  47  ( FIG. 4 ), however, but it is generally true for some embodiments that the greater the pressure in the fuel supply line, the more the piston  7  is forced towards a closed position. 
       FIG. 3A  is a close-up of a side cutaway view of components and features present in a fluid delivery control device according to some embodiments of the disclosure. In  FIG. 3A  is shown fluid entry passage  40  within conduit  65  ( FIG. 2A ) which is adjacent to upstream space  44 . Piston  7  is shown in its rest position, having needle valve orifice  11  at its top end that is configured to receive and slidingly engage needle valve  13 . In some embodiments both needle valve  13  and needle valve orifice  11  are circular in their cross-sectional dimension; however, any other cross-sectional dimensions of these elements are suitable for use in a fueling nozzle  10  according to this disclosure provided the same function as described herein is achieved. In general the cross-sectional dimension of needle valve  13  is smaller than the cross sectional dimension of needle valve orifice  11  sufficiently to enable flow of fuel present in fluid entry passage  40 , present in upstream space  44 , into the interior volume  48  of piston  7 . Thus, a gap exists in some embodiments between needle valve orifice  11  and needle valve  13 , having any effective dimension suitable to enable for the function described herein. In some non-limiting, exemplary embodiments this gap is any gap having any selected cross-sectional area between two and three square millimeters, including all gaps and ranges of gaps therebetween. In some embodiments, this gap is donut-shaped. 
     Piston  7  is slidably disposed in a bore  89 , which bore  89  is in some embodiments contained within and in, other embodiments an integral part of, bore housing  9 . Piston  7  is fitted with a seal  15  at its upper shoulder, seal  15  extending coextensively about the upper shoulder of piston  7  sufficient to create a sealing arrangement between the upper shoulder of piston  7  and the inner wall of upper housing  3  where seal  15  contacts upper housing  3  when fueling nozzle  10  is in a state of non-use. 
     Bore housing  9  is attached to upper housing  3  and lower housing  5  by supports  87  attached to both the bore housing and at least one of upper housing  3  and lower housing  5 . Supports  87  are in some embodiments configured to permit flow of liquid from the space above them, to the space beneath them as indicated by the arrows in  FIGS. 5, 6 . In some embodiments supports  87  are part of bore housing  9  and are sandwiched inbetween upper housing  3  and lower housing  5 , which also aligns upper housing  3 , lower housing  5 , and bore housing  9  axially with one another. In some embodiments upper housing  3  and lower housing  5  are separate elements, each having a mating lip and joined as shown and held together by a securement  39 , which in some embodiments is a clamp and in other embodiments a clamping collar. In some embodiments upper housing  3  and lower housing  5  can be permanently affixed to one another, such as by welding. In some embodiments, upper housing  3  and lower housing  5  are bolted together, and securement  39  functions as a wear ring or guard to protect the flanges present on upper housing  3  and lower housing  5 . 
     Bore housing  9  includes a bore  89  within which piston  7  is slidably disposed. Bore housing  9  in some embodiments includes a seal  17  which can be an o-ring or like seal that runs coextensively about piston  7 . Bore housing  9  includes a central tower  85 . Central tower  85  has an upper portion and a lower portion, with the upper portion being configured to receive and maintain the end base  19  of needle valve  11  in a stationary position. Central tower  85  includes a passage  23  disposed through its interior, which passage  23  runs all the way through the lower portion of central tower  85 , terminating at a planar surface having a seal  43  ( FIG. 4 ) disposed thereabout that is configured to sealingly engage with the face of tilt valve  27 . In some embodiments, seal  43  is disposed on the surface of or embedded within tilt valve  27  as selected, and seal  43  moves with movement of tilt valve  27 . Present along the length of passage  23  are provided ports  21 , which provide a fluid communication passageway that permits the passage of liquid fuel from piston inner volume  48  or bore space  51  into passage  23 , responsive to movement of tilt valve  27  off of its seat  43  ( FIG. 4 ) such as by deflection of tilt valve shank  25  as a result of movement of actuator lever end  32 . 
     Dispensing lever  29  is shown in  FIG. 3A , having an end  33  that is pivotally connected to one end of link  35 , the other end of link  35  being pivotally connected to a stationary location  41  on body  5 . Activator shaft  31  is also pivotally connected at  91 , at its first end to dispensing lever  29 , the second end of dispensing lever being in effective mechanical contact with tilt valve shank  25 . In some embodiments the end of activator shaft  31  which actuates tilt valve shank  25  contains a tubular section that extends about the end of tilt valve shank  25 , as shown. 
     In  FIG. 4  is shown a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of the disclosure in a closed position, depicting the location of spring  47  which was omitted from the description of  FIG. 3A  for reasons of, clarity of other components present. Spring  47  has a first end which resides in a spring seat  49  present in bore housing  9 , and the second end of spring  47  is disposed sufficiently to mechanically bias piston  7  towards a closed position such that seal  15  present at or on the shoulder of piston  7  engages the inner wall of upper housing  3  to prevent fuel being dispensed from passing from upstream space  44 , (space that is upstream to the location at which valving is effected) to downstream space  46  (space that is downstream to the location at which valving is effected). In alternate embodiments, seal  15  is present in or on the wall of upper housing  3  and sealingly engages the shoulder of piston  7 . In some embodiments, the interior contour of piston  7  is configured to receive spring  47  in such a biasing arrangement. In some exemplary, non-limiting embodiments, spring  47  has a diameter of 4.01 centimeters and a free length of 11.43 centimeters. In some exemplary, non-limiting embodiments the installed height of spring  47  is 4.30 centimeters, and spring  47  exerts a force of about 26 Newtons at this height. In some exemplary, non-limiting embodiments, spring  47  has 11 coils and is made from any suitable spring steel having a circular cross-section that is 2.16 millimeters in diameter. Some exemplary, non-limiting embodiments of a fueling nozzle  10  having a spring with the features and gap mentioned above is capable of withstanding a line pressure at fluid entry passage  40  of three pounds per square inch (“psi”) without the seal  15  about piston  7  being moved to enable liquid flow past piston  7  to downstream space  46 , and the diameter of passage  23  is 3.81 millimeters. When seals are present about the pertinent elements, a stronger closing force of piston  7  results, as line pressure is increased due to piston  7  being overbalanced. Of course such specific dimension of passage  23  and other features specified are merely exemplary of some embodiments of this disclosure, those of ordinary skill in this art once understanding the teachings hereof find it simple to make routine adjustments to parameters and values specified without any undue level or burden of experimentation. A further advantage still of the teachings provided herein is the elimination of a check valve  73  as compared to prior art fueling nozzles, as the necessity of such check valves have been rendered redundant by the function of fueling nozzles of the present disclosure as a whole. 
       FIG. 3B  shows a close-up side cutaway view of components present in a fluid delivery control device according to some embodiments of this disclosure, showing the piston  7 , seal  15 , upstream space  44 , piston interior volume  48 , and upper housing  3 . Upper housing  3  includes a bore therethrough having wall  52 . The bore having wall  52  is of any selected appropriate diameter D 1  and in some embodiments piston  7  features a crown having a vertical wall  54  which is circular in configuration from an overhead perspective and has a diameter D 2 . In some exemplary, non-limiting embodiments, the D 2  is dimensioned the be slightly smaller than the diameter D 1 , by an amount between 0.1 and 0.2 millimeters, which provides for piston  7  choking the flow of liquid passing from upstream space  44  to downstream space  46 , prior to the seating of seal  15 . In some exemplary embodiments, D 1  is 3.87 centimeters, and D 2  is 3.86 centimeters. Such feature of piston  7  being contoured to choke off flow of liquid from upstream space  44  to downstream space  46  prior to engagement of seal  15  results in vast reduction of line shock and recoil when it is desired to stop liquid flow, compared to prior art fueling nozzles. 
     In  FIG. 4  is also shown return spring  147  having two ends, the first end being seated against bushing  37  and the second end being seated against actuator lever end  32 . Return spring  147  maintains tilt valve shank  25  in the position shown in  FIG. 4  when dispensing lever  29  is at its rest position, as shown, thus allowing tilt valve  27  to remain sealed against seal  43  precluding any liquid present in piston interior volume  48  from flowing through ports  21  and out of passage  23  into downstream space  46 . The same function is achieved when seal  43  is selected to be present in or on tilt valve  27 . 
       FIG. 5  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of the disclosure in a partially-opened position, in which liquid fuel is permitted to flow from upstream space  44 , past piston  7  through opening  77 , to downstream space  46 , as indicated by the arrows thereon. As seen in  FIG. 5 , piston  7  has moved downward with respect to its normally-closed location shown in  FIG. 4 , due to dispensing lever  29  having been moved to the right as indicated by the arrow, such as by the grasp of a user&#39;s fingers. Motion of dispensing lever  29  to the right in  FIG. 5  causes activator shaft  31  to pull on tilt valve shank  25 , thus moving tilt valve  27  off of seal  43 , creating opening  45 . The same function is achieved when seal  43  is selected to be present in or on tilt valve  27 . Such creation of opening  45  permits liquid fuel present in piston interior volume  48  to flow through ports  21 , into passage  23  and finally out of opening  45  and into downstream space  46 , thereby reducing the upward force on piston  7 , which allows piston  7  to move downward as it seeks to find an equilibrium position of fluid flowing into piston interior volume  48  vs. liquid flowing out of piston interior volume  48 , such as to the position shown in  FIG. 5 . More liquid fuel enters piston interior volume  48  through needle valve orifice  11  ( FIG. 4 ) through the gap between needle valve  13  and needle valve orifice  11 . The downward movement of piston  7  continues for each degree of further movement to the right of dispensing lever  29  until dispensing lever  29  is kept in a stationary position, at which point an equilibrium will be reached between the downward force on piston  7  by the line pressure of liquid fuel in upstream space  44  and the upward force on piston  7  by the liquid fuel contained within piston interior volume  48 . These pressures are dependent on the line pressure of the liquid fuel, the pre-selected size of the gap between needle valve  13  and needle valve orifice  11 , the area on the topside of piston  7  exposed to line pressure in upstream space  44 , the area of the interior of piston  7 , and the effective liquid pressure present in the interior of piston  7 . As piston  7  moves upward or downward, it closes or opens the passageway (opening  77 ) through which liquid can flow. In view of this disclosure, it is thus a relatively simple matter now to determine any level of force desired to be acting on piston  7  for various dimensions of a device as taught herein to be selected, for any selected degree of line pressure in upstream space  44 . In general, the characteristics of spring  47  are selected to that when there is no line pressure at upstream space  44 , piston spring  47  maintains piston  7  in the closed position. The presence and configuration of tilt valve  27  results in easy operation of fueling nozzle  10  with minimal grasping force by the user, regardless of the line pressure, and provides extremely smooth throttling of fuel flow. 
       FIG. 6  is a close-up of a side cutaway view of components present in a fluid delivery control device according to some embodiments of the disclosure in a fully-opened position, piston  7  having become totally bottomed-out and at the lowermost extreme point of its possible travel, by virtue of the sealing face or other pertinent portion of tilt valve  27  having been either sufficiently or maximally removed away from seal  43 , (in alternate embodiments when seal  43  is selected to be present in or on tilt valve  27  being so moved to permit flow through passage  23 ) and the remainder of fueling nozzle  10  ( FIG. 2A ) being dimensioned sufficiently that by such action the downward force of liquid or liquid fuel passing from upstream space  44  to downstream space  46  completely overcomes the upward force exerted by spring  47 , there being effectively no net upward force within piston interior volume  48  due to near total bleed-off of liquid passing through ports  21  and passage  23 . The position of piston  7  in  FIG. 6  represents the situation when the valve arrangement within fueling nozzle  10  is “full open” and permits the maximum flow of liquid from upstream space  44  to downstream space  46 . 
     For some degrees of opening of tilt valve  27 , the volume of fluid flowing into piston interior volume  48  through needle valve orifice  11  is equal to the volume of fluid flowing out of passage  23  past seal  43  ( FIG. 4 ). As tilt valve  27  is opened further, piston  7  “floats” further down so that the location of needle valve orifice  11  is at a location about the shank of needle valve  13 . By contouring the shank of needle valve  13  to be tapered to any selected degree, it is possible to control the location of piston  7  in fueling nozzle  10  for any degree or amount of opening of tilt valve  27  selected by engineers. 
     In addition to the several functions, features, and synergies provided herein, another valuable feature of a nozzle  10  according to this disclosure is, when there is no line pressure, i.e., the pump supplying fuel or other selected liquid under pressure to nozzle  10  is not operating, piston  7  is spring-biased in a closed position and can accordingly not open to permit latent fuel or other liquid in the conduit supplying nozzle  10  to flow onto pavement or the ambient surroundings. In addition, upon initial opening of piston  7  during a re-fueling operation, as depicted in  FIG. 7 , only a tiny amount of fuel escapes from passage  23  prior to commencement of flow of liquid fuel from upstream space  44  to downstream space  46 , typically about ten milliliters. This amount is not significant enough to cause draining of liquid fuel from the supply hose attached at fluid entry  63  ( FIG. 2A ) since piston  7  remains in a closed position with seal  15  engaged. When using prior art devices, a significant amount of fuel in the line was lost, and un-metered, which translates to lost revenues for the fuel providers dealing in large volumes, such as providers who re-fuel commercial aircraft. Thus, the present invention solves a long-standing issue in the art of refueling, whereby oil companies using prior art devices were not able to collect revenue for all fuel consumed. 
       FIG. 8  is a side cutaway view of components present in a fluid delivery control device according to some embodiments of the disclosure, illustrating a pressure-maintaining valve subassembly comprising ball  91 , spring  93 , and bushing  95 . Spring  93  and ball  91  are disposed within passage  23  of tower  85  sufficiently so that ball  91  is mechanically-biased towards blocking the opening of port(s)  21 . Bushing  95  rests on or in proximity to base  84  of tower  85  and serves as a spring seat to provide stability for the stationary end of spring  93 . The non-stationary end of spring  93  is disposed to be in contact with ball  91 , there maintaining a mechanical bias on ball  91  when ball  91  is pressed against the top of passage  23  within tower  85 . In some exemplary, non-limiting embodiments, spring  93  is selected so that the pressure present in port(s)  21  exceeds ambient pressure by about 6.6 pounds per square inch in order to cause motion of ball  91  to compresses spring,  93  thus opening port(s)  21 . In other embodiments spring  93  is selectable by engineers depending on end-use requirements, so that the pressure present in port(s)  21  must exceed ambient pressure by any desired amount between one pound per square inch and 100 pounds per square inch, or any pre-selected pressure, in order to cause motion of ball  91  to compresses spring,  93  thus opening port(s)  21  under sufficient pressure. 
     Thus ball  91 , spring  93 , and bushing  95  when collectively selected to be present as described herein permits fluid to flow from port(s)  21  into passage  23 , but not vice versa. In some field end-uses, when there is a very low pressure in the supply line attached to a fueling nozzle  10 , if tilt valve  27  is actuated, fuel can slowly make its way out of the tilt valve. Addition of a pressure-maintaining valve as herein described will increase the amount of pressure required before fuel is permitted to flow from port(s)  21  into passage  23 , thus permitting custom tuning of the performance of a fueling nozzle  10 . Thus, with appropriate selection of spring  93 , a system can be readily provided in which fueling nozzle  10  will not dispense any fuel at all, unless the pressure in the fuel supply line to nozzle  10  is at least that of any pre-selected threshold value based on the stiffness of spring  93 . Ball  91  also functions in some embodiments to prevent air entering piston interior volume  48 . As mentioned above, in some field end-uses, when there is a very low pressure in the supply line attached to a fueling nozzle  10 , if tilt valve  27  is actuated, fuel can slowly make its way out of the tilt valve. Simultaneously, however, air can also be admitted into piston interior volume  48 , which can lead to a leakage scenario. One instance could be when an operator brings the supply line pressure to a fuel nozzle  10  up to operating pressure very quickly, the surge in the line pressure causes an impact force which can act on the top of piston  7 . With substantial air or other gas present in piston interior volume  48 , the air present therein is compressed upon such impact force, and piston  7  can momentarily move, permitting fuel to momentarily pass through opening  77  ( FIG. 6 ). Any other known or prior art check valve subassembly that is apparently suitable for use in a nozzle  10  as provided herein may be selected and employed. 
       FIG. 8  also illustrates an alternative embodiment having the rear face of tilt valve  27  equipped with a seal  143  and being spring-biased towards a closed position. The present disclosure includes further alternate embodiments when such a configuration of tilt valve as shown in  FIG. 8  is employed, that ball  91  and spring  93  are omitted. 
     In some embodiments both of said fluid entry passage  40  and fluid exit passage  42  are conduits each having a circular cross section and a center. In some embodiments the centers of each of said fluid inlet passage and said fluid exit passage are substantially aligned with one another. Such configuration makes a nozzle  10  according to this disclosure to be useful by a re-fueling technician or other personnel in an orientation such as that shown in  FIG. 2B , as opposed to fueling nozzles of prior art which are only useful as shown in  FIG. 1B . 
     Consideration must be given to the fact that although this invention has been described and disclosed in relation to certain embodiments, equivalent modifications and alterations thereof may become apparent to persons of ordinary skill in this art after reading and understanding this specification. The present disclosure includes subject matter defined by any combinations of any one or more of the features provided in this disclosure with any one or more of any other features provided in this disclosure. These combinations include the incorporation of the features and/or limitations of any dependent claim, singly or in combination with features and/or limitations of any one or more of the other dependent claims, with features and/or limitations of any one or more of the independent claims, with the remaining dependent claims in their original text being read and applied to any independent claims so modified. These combinations also include combination of the features and/or limitations of one or more of the independent claims with features and/or limitations of another independent claims to arrive at a modified independent claim, with the remaining dependent claims in their original text or as modified per the foregoing, being read and applied to any independent claim so modified.