Abstract:
An apparatus, system, and means are disclosed for a modular backpressure sensor configured for use with a fluid delivery nozzle. The modular backpressure sensor may be installed and removed using simple tools and may optionally include an activator handle attachment. The system may optionally include a protective end plug for the fluid delivery nozzle.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   This invention relates to a removable pressure calibration module installed in a pressure sensitive fluid delivery nozzle. One embodiment relates to a system for fueling large vehicles. 
   2. Description of the Related Art 
   Large construction and mining vehicles are often equipped with a fueling system that allows the fuel tank to be filled from the bottom. This enables the fueling of the vehicle to take place from ground level as many of the vehicles of this type are extremely large. There are two types of fueling systems that allow fueling from the bottom of the tank. They both incorporate three common components: 1) a fueling nozzle that senses a pressure change in order to shut off, 2) a fueling receiver that is permanently attached to the fuel tank to which the nozzle attaches, and 3) a fuel vent that can sense when the fuel tank is filled and provide a pressure change that can be sensed by the nozzle. One system uses a vent that closes an exhaust port when the fuel tank is full allowing the tank itself to become pressurized by the incoming fuel. The fuel nozzle senses this pressure and shuts off at a pre-determined pressure level. The second type of system uses a vent that is attached by one or more hoses to the fuel receiver. When the tank is full, the vent provides a pressure change to one or more of the hoses which causes a valve in the fuel receiver to change position which in turn causes the fuel nozzle to shut off. In some systems, the same fuel nozzle can be used in conjunction with different combinations of vents and receivers to provide either a pressure operated system (tank is pressurized) or a non-pressurized system (the tank is not pressurized). 
   Most fuel nozzles of this type incorporate a pressure sensing device. Most fuel nozzles, in current use, incorporate either a spring biased piston or diaphragm to sense the change in back pressure of the fuel flowing through the nozzle. The change in back pressure causes the nozzle to shut off when the pressure reaches a pre-set pressure. The pressure is typically calibrated and pre-set by mounting the entire nozzle on specialized equipment in a repair shop. Moreover, the nature of its function subjects the pressure sensing component to a significantly greater rate of wear than the other parts of the nozzle. 
   Due to the extreme conditions of use, the nozzles typically require frequent rebuilding—often after every few months or even after every few weeks of operation. The entire nozzle must be returned to a rebuild center to be completely disassembled, reassembled with certain potentially new components, and tested as a unit on a fairly complex test stand. Only a few fully equipped rebuild sites exist. This requires that complete back up sets of these expensive nozzles be kept on hand at the mining and construction sites for use while a first set of nozzles is being rebuilt. 
   Additionally, some fueling systems physically restrict the diameter of the delivery end of the fueling nozzle. At one time, most nozzles incorporated a rubber bumper on the end of the fuel nozzle to provide physical protection from incidental damage when the nozzle was not in use. Because of the new diameter restrictions, many users remove the rubber bumpers in order to fit on the newer fuel receivers, thus removing an important damage prevention feature of the nozzles. 
   From the foregoing discussion, it should be apparent that a need exists for an apparatus, system, and method that allows the pressure sensing component to be removed and replaced modularly on site. Beneficially, such an apparatus, system, and method would also allow the end user to repair, set, and calibrate the module, obviating the need for use of a rebuild center. A need also exists for a related apparatus, system, and method to protect the end of the nozzle when the nozzle is not in use. Beneficially, such an apparatus, system, and method, would be adaptable to various diameter restrictions of the fuel receiver. 
   SUMMARY OF THE INVENTION 
   The present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available fuel nozzles. Accordingly, the present invention has been developed to provide an apparatus, system, and method for a pressure sensing component that can be removed and repaired on site, and that thus overcomes many or all of the above-discussed shortcomings in the art. 
   This allows an end user, for example a mine site, to quickly rebuild worn nozzles without sending the entire unit to a dedicated rebuild center. This not only saves direct costs associated with shipping and handling but also provides an increased safety margin in that a fuel soaked nozzle is not shipped to another facility. End users see a significant savings in rebuild costs by rebuilding the nozzles so quickly within their own facilities and without the need for specialized tools or calibration devices. 
   The modular backpressure sensor essentially comprises a pressure sensing chamber defined by a modular housing. The pressure sensing chamber is configured to communicate with the fluid flow channel of the fluid delivery nozzle and is equipped with a pressure sensing device or material. The pressure response member responds to pressure within the fluid flow channel of the nozzle by activating the shut-off valve within the fluid delivery nozzle. A biasing member reacts to pressure on the pressure response member. A retainer retains either or both of the biasing member and the pressure response member within the modular housing. 
   The modular backpressure sensor is configured to removably engage a fluid delivery nozzle having a body with an outlet configured to engage a fluid storage tank connector and an inlet configured to engage a fluid delivery hose. A flow channel within the fluid delivery nozzle permits fluid flow from the inlet to the outlet and is configured to accommodate a shut-off valve. The shut-off valve is configured to cooperate with a stopper configured to block the flow of fluid through the valve. The fluid delivery nozzle comprises an interface configured to engage the modular backpressure sensor and to communicate backpressure to the modular backpressure sensor. 
   Together the modular backpressure sensor and associated fluid delivery nozzle comprise a system for delivering fluid to a receptacle. The fluid delivery nozzle is configured to removably engage the modular backpressure sensor. The fluid delivery nozzle body has an outlet configured to engage a fluid receiving tank connection and an inlet configured to engage a fluid conductor such as a hose. A flow channel in the fluid delivery nozzle body permits fluid flow from the inlet to the outlet. The flow channel includes a shut-off valve configured to block the flow of fluid through the flow channel. The fluid delivery system also includes a fluid receiving tank connection which may engage the fluid outlet of the fluid delivery nozzle and a fluid conductor with a nozzle connection which may engage the fluid inlet of the fluid delivery nozzle. 
   The present invention also includes a modular backpressure sensor kit for maintaining a fluid delivery nozzle having a modular backpressure sensor. The kit may include at least one modular backpressure sensor calibrated to operate in cooperation with the fluid delivery nozzle and optionally may include other maintenance and repair elements such as tools, replacement sealing rings, replacement bushings, and replacement snap rings. 
   A means for a sensing fluid backpressure from a fluid receptacle is disclosed. The means comprises modular means for sensing fluid backpressure, means for removably connecting the modular means for sensing fluid backpressure to a fluid delivery nozzle, means for communicating fluid back pressure within a fluid flow channel of the fluid delivery nozzle to the modular means for sensing fluid backpressure, means for generating a backpressure response within the modular means for sensing fluid backpressure and means for communicating the generated backpressure response to a shut-off valve within the fluid flow channel. 
   Reference throughout this specification to features, advantages, or similar language does not imply that all of the features and advantages that may be realized with the present invention should be or are in any single embodiment of the invention. Rather, language referring to the features and advantages is understood to mean that a specific feature, advantage, or characteristic described in connection with an embodiment is included in at least one embodiment of the present invention. Thus, discussion of the features and advantages, and similar language, throughout this specification may, but do not necessarily, refer to the same embodiment. 
   Furthermore, the described features, advantages, and characteristics of the invention may be combined in any suitable manner in one or more embodiments. One skilled in the relevant art will recognize that the invention may be practiced without one or more of the specific features or advantages of a particular embodiment. In other instances, additional features and advantages may be recognized in certain embodiments that may not be present in all embodiments of the invention. 
   These features and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the advantages of the invention will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which: 
       FIG. 1  is a cross-section diagram illustrating a lateral section of one embodiment of an assembled modular backpressure sensor; 
       FIG. 2  is an exploded view of one embodiment of a modular backpressure sensor; 
       FIG. 3  is a perspective cross-section diagram illustrating a fluid delivery nozzle with a modular backpressure sensor installed in accordance with one embodiment of the present invention; 
       FIG. 4  is a schematic cross-section diagram illustrating a fluid delivery nozzle with a modular backpressure sensor installed in accordance with one embodiment of the present invention; 
       FIG. 5  is a schematic block diagram illustrating one embodiment of a system for fluid delivery using a modular backpressure sensor; and 
       FIG. 6  is a schematic block diagram illustrating one embodiment of a modular backpressure sensor kit. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Many of the functional units described in this specification have been labeled as modules, in order to more particularly emphasize their implementation independence. 
   Furthermore, the described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to facilitate a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention. 
     FIG. 1  is a cross-section diagram of one embodiment of an assembled modular backpressure sensor  100 . As depicted, the modular backpressure sensor  100  comprises a modular housing  102 , a backpressure piston  104 , a piston spring  106 , a piston spring retainer  108 , a housing head  110 , a fluid pressure chamber  112 , a piston rod  114 , a longitudinal bore  116 , a forward radial bore  118 , a fluid pressure chamber radial bore  120 , a backpressure piston extension  122 , a lateral groove  124 , a housing head aperture  126 , and a bushing  128 . 
   The modular housing  102  contains the backpressure piston  104  and the piston spring  106 . The backpressure piston  104  forms a fluid impermeable seal with the walls of the modular housing  102 . The piston spring retainer  108  confines the piston spring  106  within the modular housing  102 . The housing head  110  seals the forward end of the modular housing  102  and cooperates with a wall of the modular housing  102  and the piston  104  to define the fluid pressure chamber  112  between the backpressure piston  104  and the housing head  110 . As depicted, the modular housing  102  has a circular cross-section. In alternative embodiments, the modular housing  102  may have an elliptical or other non-circular cross-section. 
   In the illustrated embodiment the piston rod  114  passes through the cylinder head aperture  126  and connects to the backpressure piston  104 . The bushing  128  aligns the piston rod  114  with a longitudinal axis  115  of the modular housing  102 . Fluid enters the piston rod  114  through the forward radial bore  118  and flows through the longitudinal bore  116  and enters the fluid pressure chamber  112  through the fluid pressure chamber radial bore  120 . The flowing fluid fills the fluid pressure chamber  112  and the pressure moving the fluid begins to build in the fluid pressure chamber. Alternatively, a flexible diaphragm in the housing head  110  may transfer pressure from a fluid in the piston rod  114  to a fluid such as a gas within the fluid pressure chamber  112 . In yet another embodiment, the pressure of the fluid in the piston rod  114  is registered by an electronic pressure sensor in communication with the fluid flowing in the piston rod  114 . 
   Increasing pressure within the fluid pressure chamber  112  drives the backpressure piston  104  back against the resistance of the piston spring  106 . In a further embodiment, a compressible solid, gas, liquid, or other resilient material may be used in place of the piston spring  106  to provide resistance. 
   The movement of the backpressure piston  104  retracts the piston rod  114  in direction  130 . The piston extension  122 , with its lateral groove  124  serves as an attachment site for an activation handle (See  FIG. 3 ). 
     FIG. 2  is an exploded view of the modular backpressure sensor  100  illustrated in  FIG. 1 . As depicted, in addition to the parts identified in  FIG. 1 , the modular backpressure sensor  100  comprises snap rings  202  and  204 , O-ring channels  206 , O-rings  208 , bushing snap ring  210 , and backpressure piston seal  212 . 
   In the depicted embodiment snap ring  202  engages an interior channel in the modular housing  102  and secures the piston spring retainer  108 . Snap ring  204  engages an interior channel in the modular housing  102  and secures the housing head  110 . The snap rings  202 ,  204  prevent internal components within the housing  102  from escaping in response to the forces imposed by the spring  106  and fluid force within the fluid pressure chamber  112 . The O-ring channels  206  receive and retain the O-rings  208 . The O-rings  208  retain the modular housing  102  within an opening within a fluid nozzle. The bushing snap ring  210  engages a channel  127  in the bushing  128 . The bushing snap ring  210  secures the bushing  128  to the housing head  110 . The backpressure piston  104  incorporates an annular channel to accept a backpressure piston seal  212  that forms a fluid impermeable seal with the interior wall of the modular housing  102  such that fluid is retained within the fluid pressure chamber  112 . 
   In an alternative embodiment, the housing head  110  may be formed as an integral part of the modular housing  102 . Additionally, the housing head  110  maybe formed as a cap that attaches to the modular housing body by means of threads, grooves, flanges, clips, or other fastening means. In another embodiment, the piston spring retainer  108  may be formed as an integral part of the modular housing  110 . The piston spring  106  may be removed from the modular housing  110  through an opening configured to accommodate a removable housing head  110 . The piston spring retainer  108  may also be formed as a cap that attaches to the modular housing body by means of threads, grooves, flanges, clips, or other fastening means. In embodiments with an integrated housing head  110  or piston spring retainer  108 , snap rings  202  or  204  may not be required. 
     FIG. 3  is a cross-section diagram illustrating one embodiment of a combined fluid delivery apparatus  300  comprising a fluid delivery nozzle  301  configured to receive a modular backpressure sensor  100 . As depicted, the combined apparatus  300  comprises a modular backpressure sensor  100 , an actuator handle  302 , a nozzle body  304 , a removable back plate  306 , a piston rod  114 , a sealing poppet  308 , a fluid intake port  310 , a fluid flow channel  312 , a fluid outlet port  314 , a pull-back handle  318 , a carry handle  320 , a fluid shut-off valve  322  and a nozzle pressure cavity  324 . 
   In operation, the fluid intake port  310  connects to a fluid conductor hose. The pull back handle  318  cocks the fluid outlet port  314  for connection to a receptacle connector. The carry handle  320  facilitates transport of the nozzle  301 . 
   The activator handle  302  cooperates with the modular backpressure sensor  100  to extend the piston rod  114 , pushing the sealing poppet  308  forward to open the fluid shut-off valve  322 . The removable back plate  306  detaches to allow withdrawal of the modular backpressure sensor  100  from the nozzle pressure cavity  324 . 
   The back plate  306  may be removed with standard tools, permitting access to the modular backpressure sensor  100 . Preferably, the back plate  306  is secured to the nozzle  301  by way of common fasteners such as screws, nuts, thumb-screws, thumb-nuts, or the like. 
   The sealing poppet  308  may also be removed using standard tools such as needle nose pliers, a screw driver, or, alternatively, a poppet spanner wrench. When the back plate  306  and poppet  308  have been removed, the modular backpressure sensor  100  can be withdrawn from the rear of the nozzle body  301 . The modular housing  102 , the housing head  110 , and the piston spring retainer  108  are preferably made of rigid, fluid insoluble, materials of sufficient size and thickness to withstand the pressure exerted by the piston spring  106  and by fluid within the pressure sensing chamber  112 . In one embodiment, the modular housing  102 , the housing head  110 , and the piston spring retainer  108  are made of hard plastic, aluminum, stainless steel, or the like. 
   The robust nature of the modular housing  102 , the housing head  110  and the piston spring retainer  108  facilitate the modular nature of the modular backpressure sensor  100 . Moreover, the modular backpressure sensor  100  can be safely and conveniently removed and replaced. In standard existing fluid delivery nozzles, the piston spring sits directly within the nozzle backpressure chamber and is retained by a back plate. However, the back plate must be removed using specialized tools. Due to the bias forces within the spring of conventional fluid delivery nozzles, removal of the back plate without the special tools can cause the piston spring to violently ejects from the nozzle body creating a risk of potentially serious injury, especially to the eyes and face of a user. 
   Alternatively, the fluid delivery nozzle  301  may lack a nozzle pressure cavity  324  and the modular backpressure sensor  100  may engage the fluid delivery nozzle  301  directly, with the modular housing  102  exposed. Additionally, the modular backpressure sensor  100  may be connected to substantially any external surface of the fluid delivery nozzle  301 . 
   In a further embodiment the modular backpressure sensor  100  may incorporate electronic, digital, or analog elements to supplement or replace the mechanical elements. In such an embodiment the modular backpressure sensor  100  may interact with the fluid delivery nozzle  301  through a sensing and communication element and may directly connect to the fluid delivery nozzle  301  or reside in a remote location. Such an embodiment would include a power source, an electronic modular backpressure sensor, and a shut-off switch. The shut-off switch may be configured to trigger an electronic or mechanical shut-off mechanism within the fluid delivery nozzle. 
     FIG. 4  is a cross-section diagram illustrating a lateral section of one embodiment of a combined fluid delivery apparatus  300 . As depicted, the combined apparatus  300  comprises a fluid delivery nozzle  301 , a modular backpressure sensor  100 , a cam  402 , a piston pin  404 , a cam cavity  406 , a valve spring  408 , a pull-back spring  410 , a release dog  412 , a sleeve spring  414 , a pull-back sleeve  416 , a dog ring  418 , an axle  422 , a nub  426 , and a tooth  428 . 
   The pull-back handle  318  cocks the nozzle  301  for attachment to a receptacle connector (not shown). Cocking the nozzle  301  prepares the nozzle  301  for engaging the receptacle connector. Pulling back on the pull-back handle  318  moves the attached pullback sleeve  416  toward the rear of the nozzle  301 . Backward movement of the pullback sleeve  416  releases the release dogs  412  that extend around the inner circumference of the fluid outlet port  314  of the nozzle body. A nub  426  on the inside wall of the pullback sleeve  416  slides along a release dog  412  and forces the release dog  412  to pivot and extend a tooth  428  of the release dog  412 . The release dogs  412  open to increase the effective diameter between release dogs  412 . The pull-back motion of the pullback sleeve  416  biases the sleeve spring  414  which facilitates return of the pull-back sleeve  416 . 
   Once, the nozzle  301  is inserted into a receptacle connector, the pull-back handle  318  is moved forward with assistance from the pull-back spring  410 . The nub  428  forces the release dogs  412  to close causing the release dogs  412  to clamp down on the receptacle connector and engage the receptacle connector. The dog ring  418  locates the release dogs  412  in either an open when the pull-back handle  318  is moved backward and in a closed position when the pull-back handle  318  is moved forward. Cocking the pull-back handle  318  locks the release dogs  412  in open position, allowing the nozzle  300  to be attached to or removed from a receptacle connector. 
   The activator handle  302  turns on axle  422  which in turn actuates cam  402  within cam chamber  406 , exerting pressure on the piston pin  404  and on the backpressure piston extension  122 . Moving the activator handle  302  to pivot in a counter-clockwise direction about the cam  402  allows the piston spring  106  to move the backpressure piston extension  122 , the backpressure piston  104 , the piston rod  114  and associated poppet  308  forward, opening the fluid shut-off valve  322 . The fluid shut-off valve  322  is pressed against the valve spring  408  into a retracted position by the receptacle connector to which the nozzle  301  is attached for operation. Therefore, removal of the receptacle connector closes the valve spring  408 . 
   Downward pressure on the activator handle  302  retracts the piston extension  122  and its associated structures including the poppet  308 . This allows the poppet  308  to seal against the fluid shut-off valve  322  which in turn stops fluid flow through the nozzle. Such downward pressure causes the activator handle  302  to pivot in a counter-clockwise direction about the cam  402  and retracts the piston extension  122  and the poppet  308  to close the fluid shut-off valve  322 . 
   Downward pressure on the activator handle  302  retracts the piston extension  122  and its associated structures including the poppet  308 .  FIG. 4  also illustrates the cross-section shape of the piston pin  404 . In particular the piston pin  404  includes two opposing flattened edges  430 . These edges  430 , together with linkage  432  translate the rotational movement of the handle  302  about the cam  402  into lateral movement to move the poppet  308 . 
     FIG. 5  is a schematic block diagram illustrating one embodiment of a system  500  for fluid delivery using a modular backpressure sensor. As depicted, the system  500  comprises a fluid source  502 , a fluid conductor  504 , a nozzle connection  506 , a fluid delivery nozzle  301 , a modular backpressure sensor  100 , a receiver connection  508 , a fluid receiver  510 , and a replacement modular backpressure sensor  512 . 
   The fluid source  502  may be a fuel, oil, water, or other fluid storage tank. In addition, the fluid in the fluid source  502  may comprise a material in a liquid, gas, or semi-solid state. The fluid conductor  504  transfers the fluid from the fluid source  502  to the nozzle connection  506 . The fluid conductor  504  may be a hose, conduit, pipe, or other conducting apparatus. 
   The fluid delivery nozzle  301  and associated modular backpressure sensor  100  (discussed above) are removably connected or coupled to the fluid conductor  504  by way of the nozzle connection  506 . The nozzle connection  506  may be fixed to the fluid conductor  504 . 
   The receiver connection  508  may be fixed or removably connected to the fluid receiver  510 . The fluid delivery nozzle  301  starts and stops fluid delivery to the fluid receiver  510 . The modular backpressure sensor  100  cooperates with the fluid delivery nozzle  301  to automatically shut-off fluid flow in response to detected back pressure in the fluid delivery nozzle  301 . Consequently, the modular backpressure sensor  100  is in fluid communication with the fluid flow path  514  such that the backpressure is detectable. Preferably, the modular backpressure sensor  100  is removably connectable to the fluid flow path  514 . In certain embodiments, the modular backpressure sensor  100  is in mechanical communication with the fluid delivery nozzle  301  in order to activate a mechanical shut-off valve  322 . Alternatively, the modular backpressure sensor  100  may send an electrical signal that activates an electronic shut-off valve in the fluid delivery nozzle  301 . 
   Advantageously, the modular backpressure sensor  100  can be readily removed using common tools including a Phillips screw driver, a crescent wrench, or the like. Consequently, when an operator determines that the modular backpressure sensor  100  should be rebuilt due to wear of the spring  106 , a certain number of uses, or passage of a certain amount of time, the modular backpressure sensor  100  can be readily replaced by the replacement modular backpressure sensor  512 . Alternatively, the modular backpressure sensor  100  may be removed, rebuilt on site, and reinstalled. On site rebuilding of the modular backpressure sensor  100  may be accomplished using additional tools such as snap-ring pliers, needle nose pliers. 
   The piston spring  106 , O-rings  208 , and the piston ring  212  comprise the principle points of wear on the modular backpressure sensor. Pre-calibrated springs are available for various levels of shut-off pressure. Therefore, rebuilding of the depicted embodiment of the modular backpressure sensor  100  would usually comprise removal of the snap ring  202 , the piston spring retainer  208 , and the piston spring  106 , and replacement of the piston spring  106  with a new, pre-calibrated spring  106 . New snap rings  202 ,  204  may be installed. The snap rings  202 ,  204  may serve as a replacement fastener. Additionally, the piston  104  may be removed for seating of a new sealing ring within the piston channel  212  and the external modular housing O-rings  208  may be replaced. 
   The piston spring retainer  108  and snap ring  202  would then be reinserted into the modular housing  110  and the modular backpressure sensor  100  reengaged with the nozzle body  301 . The poppet  308  would be reinstalled on the piston rod  114 , the activation handle  302  reengaged with the piston extension  122  by means of the piston pin  404  and the back plate  306  reattached. 
     FIG. 6  is a block diagram illustrating one embodiment of modular backpressure sensor kit  600 . A typical kit  600  could include a pre-calibrated modular backpressure sensor unit  100  and associated seals  208  required for installation of the modular backpressure unit. The associated seals  208  may comprise rubber or plastic O-rings or may comprise the piston seal  212 . In another embodiment, the kit  600  may include several pre-calibrated modular backpressure sensor units  100  each calibrated for different backpressure levels. 
   The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.