Patent Abstract:
A system for determining a fluid level in a pressurizable container comprising is disclosed. The system includes a service valve having a set of wrench flats defining parallel flat surfaces, one of the wrench flats having a recess defined entirely within its flat surface, a stop-fill device interconnected with the service valve and operable to rotate a first magnet inside the service valve in proximity to the recess in proportion to the amount of fluid in the pressurizable container, and a dial assembly having a dial face and a pointer attached to a second magnet, the second magnet housed in a magnet protrusion on a side of the dial face opposite the pointer and operable to fit into the recess in the service valve such that the dial moves on the dial face proportionately to the degree of rotation of the first magnet inside the service valve. In one variation, a sensor placed in the recess or adjacent a throat of the service valve is electrically connected to a remotely located gauge for displaying a reading corresponding to the level of fluid in the container.

Full Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application is a continuation-in-part of U.S. patent application Ser. No. 11/023,664 entitled Gauge Assembly Having a Stop-fill Valve, filed Jul. 28, 2005 which claims the benefit of U.S. Provisional Application No. 60/538,279, entitled “Gauge Assembly”, filed on Jan. 22, 2004 and U.S. Provisional Application No. 60/572,143, entitled “Gauge Assembly Having a Stop-fill Device”, filed on May 18, 2004, the disclosures of which are incorporated herein by reference. This application also claims the benefit of U.S. Provisional Application Ser. No. 60/822,926, entitled “Service Valve Assembly Having a Stop-fill Device and Magnetic Liquid Level Indicator,” filed Aug. 18, 2006, U.S. Provisional Application Ser. No. 60/822,921 entitled “Gauge Assembly having a Stop-Fill Device and a Liquid Level Indicator,” filed Aug. 18, 2006 and U.S. Provisional Application Ser. No. 60/822,928, entitled “Gauge Assembly Having a Stop-Fill Device and a Liquid Level Indicating Dial” filed Aug. 19, 2006, the disclosures of which are incorporated herein by reference. 
     
    
     TECHNICAL FIELD  
       [0002]     This disclosure relates to a device capable of providing an indication of a fluid level in a tank and capable of transitioning a tank inlet between a state where fluid-flow is prevented and a state where fluid-flow is allowed.  
       BACKGROUND  
       [0003]     There are many different types of containers, tanks, vessels, and canisters that are used for storing fluids. For convenience, this document will use the term “tank” throughout to refer to what could be any kind of container, vessel, canister, tank, or the like.  
         [0004]     It is often desirable to allow for monitoring of the fluid level in a tank, particularly in cases where the tank is such that the fluid cannot conveniently be visually inspected. For this reason, many tanks are provided with devices for communicating a fluid level, for example through the use of a fluid-level gauge that can provide an indication of the amount of fluid present in a tank. There are many known examples of fluid level gauges that use a float or a capacitance to mechanically and/or electrically drive an indicator.  
         [0005]     It is also desirable in some cases to provide a stop-fill device for preventing a tank from being over-filled. Known stop-fill devices include those intended to be used in tanks that require a fluid to pass through an inlet valve in order to enter the tank. Typically such stop-fill devices include a float that rides on the surface of the fluid in the tank. As fluid is added to the tank, the float rises to a certain level at which point it causes, for example by releasing a spring, the inlet valve to close. Once the inlet valve is closed, no additional fluid can be added to the tank.  
         [0006]     It is further desirable in some cases to allow the indicating dial of the level gauge to be removable from the tank-valve assembly. For example, tanks are commonly traded-in for refilling, and the owner returning an empty tank may wish to remove the dial and use it on the newly filled tank. In other cases, the dial may be removed to prevent damage during storage or refilling.  
       SUMMARY  
       [0007]     The disclosure provides a single assembly capable of serving as a fluid-level gauge, a stop-fill device, or a combination of both. Included is a rotary function for both driving a dial and/or for activating a valve, thus reducing cost and number of parts, as well as providing a simplified operation.  
         [0008]     According to one feature, a gauge assembly is provided that comprises a shaft that rotates according to a change in fluid level, an indicator for providing an indication of the fluid level based on a rotational position of the shaft, and a stop-fill assembly for transitioning between an open configuration and a closed configuration based on the rotational position of the shaft.  
         [0009]     The stop-fill assembly can include a valve shuttle that rotates in conjunction with the rotation of the shaft and moves between an open position corresponding with said open configuration and a closed position corresponding with said closed configuration based on the rotational position of the shaft. The valve shuttle can include a flow surface at an angle to the direction of fluid flow when fluid is flowing into the tank such that the pressure of fluid flowing across the flow surface assists in rotating the valve shuttle from the open position to the closed position. The stop-fill assembly is designed taking into consideration the controlling pressure zones throughout the flow path. The flow surface in one embodiment may have two or more vanes for the purpose of imparting rotational force to the stop-fill assembly. The stop-fill assembly can include a valve body having a release slot, and the valve shuttle can have a retaining rib that engages with the release slot when the stop-fill assembly is in the closed configuration. The valve shuttle can have an upper shaft, and the gauge assembly can further comprise an indicator driving member for coupling with the indicator in order to translate a rotational position of the upper shaft into a fluid level. The valve shuttle can include a blocking member that blocks fluid flow when the valve shuttle is in the closed position.  
         [0010]     According to another aspect, a method of gauging and controlling fluid flow is provided that comprises the steps of rotating a shaft as fluid level in a tank changes, translating a rotational position of the shaft into a fluid level, and transitioning a stop-fill assembly between an open configuration and a closed configuration based on the rotational position of the shaft.  
         [0011]     According to another aspect of the present disclosure, a gauge assembly is provided that comprises a shaft that rotates according to a change in fluid level and a stop-fill assembly having a valve shuttle that rotates in conjunction with the rotation of the shaft and moves between an open position and a closed position. The valve shuttle can include a flow surface that is at an angle to the direction of fluid flow such that the pressure of fluid flowing across the flow surface assists in rotating the valve shuttle from the open position to the closed position.  
         [0012]     According to another aspect of the present disclosure, a combination overfill protection device, fluid level gauge, and service valve for use on a tank operable to contain fluids and gases is provided. The service valve has a body defining a set of wrench flats, an input port, and a tank port, at least one of the wrench flats defining a recess thereinto. The overfill protection device has a float that rotates a shaft in response to a change in fluid level, the shaft transitioning the overfill protection device between opened and closed configurations and rotating a magnet within the service valve body proximate the recess in the wrench flat. A removable gauge dial has a dial magnet housing sized to provide a friction fit into the recess in the wrench flat such that rotation of the magnet within the service valve actuates a dial magnet housed substantially in the dial magnet housing.  
         [0013]     According to another aspect of the present disclosure, a system for determining a fluid level in a pressurizable container is provided that comprises a service valve having a set of wrench flats, with one of the wrench flats having a recess of therein. A stop-fill device is interconnected with the service valve and operable to rotate a first magnet inside the service valve in proximity to the recess in proportion to the amount of fluid in the pressurizable container. A gauge having a dial face and a dial is attached to a second dial magnet, the second dial magnet housed in a magnet protrusion on a side of the dial face opposite the dial and operable to fit into the recess in the service valve such that the dial moves on the dial face proportionately to the degree of rotation of the first magnet inside the service valve.  
         [0014]     In yet another embodiment, an overfill protection system for use with removable magnetic dial gauge is provided. The system comprises a service valve defining a recess, the recess operable to receive the magnetic gauge dial in a friction fit. A shaft providing a magnet extends into the service valve and in proximity to the recess, the shaft operable to rotate the magnet in proportion to a level of fluid in contact with a float geared to the shaft. The system also comprises an overfill protection mechanism operating in response to the rotation of the shaft and moving from an open state to a closed state as the level of fluid in contact with the float increases.  
         [0015]     In another embodiment, a system for determining a fluid level in a pressurizable container is provided. The system includes a service valve having a set of wrench flats, one of the wrench flats having a first concave feature defined therein. A stop-fill device interconnected with the service valve and operable to rotate a first magnet inside the service valve in proximity to the first concave feature in proportion to the amount of fluid in the pressurizable container is provided. A gauge is also provided having a dial face and a dial attached to a second dial magnet, the second dial magnet housed in a magnet protrusion on a side of the dial face opposite the dial, the magnet protrusion defining a second convex feature that is operable to friction fit into first concave feature on the service valve such that the dial moves on the dial face proportionately to the degree of rotation of the first magnet inside the service valve.  
         [0016]     In another embodiment a system for determining a fluid level in a pressurizable container comprising is provided. The system includes a service valve having a set of wrench flats, one of the wrench flats having a first concave feature defined therein, a stop-fill device interconnected with the service valve and operable to rotate a first magnet inside the service valve in proximity to the first concave feature in proportion to the amount of fluid in the pressurizable container, and a magnetic field sensor in a sensor housing interfitting with the first concave feature. At least one signal wire is connected to the magnetic field sensor, and a fluid level display connected to the at least one signal wire to receive electrical signals corresponding to a magnetic field sensed by the magnetic field sensor and provide a fluid level display corresponding to the sensed magnetic field.  
         [0017]     A method of filling a tank using the apparatus and system described herein includes positioning a tank having cylindrical sidewall defining a central axis extending longitudinally therethrough, a generally semi-hemispherical bottom wall, a generally semi-hemispherical top wall and a service valve located on the top wall with the cylindrical in a generally vertical orientation. The service valve is connected to a source of pressurized fluid and opened to admit the fluid into the tank. The fluid is directed through a stop-fill assembly including a valve body, and a float operatively connected to a shuttle body operable to engage the valve body and block the flow of fluid into the tank. To enter the tank, fluid flows betweens the shuttle body and the valve body.  
         [0018]     Fluid flowing through the stop-fill assembly is directed radially away from the central axis of the cylinder at a location above the float. The float is lifted by filling the tank with the pressurized fluid. Fluid flow into the tank is cut off by operating the shuttle body with the float to engage the shuttle body with the valve body and block fluid flow into the tank when the fluid level in the tank reaches a predetermined level. In one aspect, the float is connected to a counterbalance with a float arm having a rotating connection with a shaft connected to the shuttle body such that the step of operating the shuttle body with the float comprises rotating the shuttle body with the float arm to move the shuttle body into engagement with the valve body. In one variation, the step of directing the fluid radially away from the central axis of the cylinder is accomplished by directing the fluid through a least one port in the valve body that extends radially away from a longitudinal axis of the shaft.  
         [0019]     In another aspect, the method also includes the step of displaying the fluid level in the tank with a level indicator operatively coupled to the float. The indicator may be a dial indicator mounted on the service valve or a remotely located indicator electrically coupled to a sensor mounted on the service valve.  
         [0020]     In yet another aspect, a gauging device for providing an indication of a fluid level in a pressurizable container includes a shaft rotating about a first axis in response to an amount of fluid in the presssurizable container, a shaft magnet attached to a first end of the shaft and a dial attached to dial magnet. The dial magnet is magnetically coupled to the shaft magnet and rotates about a second axis that is orthogonal to the first axis. In this regard, the shaft magnet rotates within a throat cavity of a gas service valve and the dial magnet rotates in proximity to the shaft magnet and exterior to the service valve. In one variation, a plane defined by the rotation of the shaft magnet is offset by a predetermined distance from the second axis of rotation.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0021]     For a more complete understanding, reference is made to the drawings, wherein like reference numbers are used herein to designate like elements throughout, and wherein:  
         [0022]      FIG. 1  shows a perspective view of a tank suitable for use with the present stop-fill device;  
         [0023]      FIG. 2  shows a perspective view of a gauge assembly incorporating the present stop-fill device;  
         [0024]      FIG. 3  is a perspective view of the stop-fill assembly included in the gauge assembly shown in  FIG. 2 ;  
         [0025]      FIG. 4  is an exploded view of the stop-fill assembly shown assembled in  FIG. 3 ;  
         [0026]      FIG. 5  is a perspective view of a valve shuttle included in the stop-fill assembly shown in  FIGS. 3 and 4 ;  
         [0027]      FIG. 6  is a perspective view of a valve body included in the stop-fill assembly shown in  FIGS. 3 and 4 ;  
         [0028]      FIG. 7  is an orthogonal view of the gauge assembly shown in  FIG. 2  in an alternate position;  
         [0029]      FIG. 8  is an enlarged view of the area in  FIG. 7  designated as  8 ;  
         [0030]      FIG. 9  is a top view of the stop-fill assembly in a closed position;  
         [0031]      FIG. 10  is a cross-sectional view of the stop-fill assembly taken along section X-X in  FIG. 9 ;  
         [0032]      FIG. 10A  is a partial cross-sectional view of the stop-fill assembly taken along section X-X in  FIG. 9 ;  
         [0033]      FIG. 11  is a cross-sectional view of the stop-fill assembly taken along section XI-XI in  FIG. 9 ;  
         [0034]      FIG. 11A  is a partial cross-sectional view of the stop-fill assembly taken along section XI-XI in  FIG. 9 ;  
         [0035]      FIG. 12  is an enlarged view of the area in  FIG. 10  designated as  12 ;  
         [0036]      FIG. 13  is a top view of the stop-fill assembly in an open position;  
         [0037]      FIG. 14  is a cross-sectional view of the stop-fill assembly taken along section XIV-XIV in  FIG. 13 ;  
         [0038]      FIG. 14A  is a partial cross-sectional view of the stop-fill assembly taken along section XIV-XIV in  FIG. 13 ;  
         [0039]      FIG. 15  is a cross-sectional view of the stop-fill assembly taken along section XV-XV in  FIG. 13 ;  
         [0040]      FIG. 15A  is a partial cross-sectional view of the stop-fill assembly taken along section XV-XV in  FIG. 13 ;  
         [0041]     FIGS.  16 A-D are perspective views of various valve shuttles having vanes;  
         [0042]     FIGS.  17 A-D are perspective end views of the valve shuttles shown in FIGS.  16 A-D;  
         [0043]      FIG. 18  is a side view of a combination service valve, stop-fill assembly, and liquid level indicator in accordance with aspects of the present disclosure;  
         [0044]      FIG. 19  is a side view of one embodiment of a stop-fill assembly in accordance with aspects of the present disclosure;  
         [0045]      FIG. 20  is a side view of one embodiment of a service valve in accordance with aspects of the present disclosure;  
         [0046]      FIG. 21A  is a front perspective view of one embodiment of a removable dial in accordance with aspects of the present disclosure;  
         [0047]      FIG. 21B  is a rear perspective view of one embodiment of a removable dial in accordance with aspects of the present disclosure;  
         [0048]     FIGS.  22 A-B are rear views with partial cutaway showing an upper portion of a combination service valve, stop-fill assembly, and removable dial in accordance with aspects of the present disclosure;  
         [0049]      FIG. 22C  is a cross section of a service valve modified for use with a removable dial in accordance with aspects of the present disclosure;  
         [0050]      FIG. 23  is a side view of another combination service valve, stop-fill assembly, and remote level indicator in accordance with aspects of the present disclosure;  
         [0051]      FIG. 24A  is an exploded view of a stop-fill assembly in accordance with aspects of the present disclosure;  
         [0052]      FIG. 24B  is a partial top view of the valve body of the stop-fill assembly of  FIG. 24A ;  
         [0053]      FIG. 24C  is a partial sectional and cutaway view of the shuttle body and valve body of  FIG. 24A ;  
         [0054]      FIG. 24D  is a partial top view of an alternate valve body for the stop-fill assembly of  FIG. 24A ;  
         [0055]      FIG. 24E  is a partial sectional and cutaway view of the alternate shuttle body and valve body for the stop-fill assembly of  FIGS. 24A and 24D ;  
         [0056]      FIG. 24F  is a partial side view of an alternate float assembly for use in connection with the stop-fill assembly of  FIG. 24A ;  
         [0057]      FIG. 24G  is a partial sectional view illustrating the stop-fill assembly of  FIG. 19A  positioned in a tank in accordance with aspects of the disclosure;  
         [0058]      FIG. 25  is a diagram illustrating one possible correlation between the magnetic field produced by an indicator magnet and a dial pointer reading or indicator according to aspects of the present disclosure;  
         [0059]      FIG. 26  is a side view illustrating the spatial relationship between a gauge magnet and a dial magnet in accordance with aspects of the present disclosure;  
         [0060]      FIG. 27  is partial sectional, partial cut-away view of a combination stop-fill assembly in accordance with aspects of the present disclosure;  
         [0061]      FIG. 27A  is a perspective view of the valve body and support member of the stop-fill assembly of  FIG. 27 ;  
         [0062]      FIG. 27B  is a top view of the valve body of the stop-fill assembly of  FIG. 27 ;  
         [0063]      FIG. 28  is an enlarged portion of  FIG. 27  enclosed by dashed lines in  FIG. 27 ;  
         [0064]      FIG. 29  is a partial sectional view of the stop-fill assembly of  FIG. 27  taken along line  29 - 29 ′ of  FIG. 27 ;  
         [0065]      FIG. 30  is a partial sectional view of the stop-fill assembly of  FIG. 27  taken along line  30 - 30 ′ of  FIG. 27 ;  
         [0066]      FIG. 31  is a perspective view of the valve shuttle of the stop-fill assembly of  FIG. 27 ;  
         [0067]      FIG. 32  is a top view of the valve shuttle of  FIG. 31 ; and  
         [0068]      FIG. 33  is an enlarged view of the portion of  FIG. 29  enclosed in dashed lines.  
     
    
     DETAILED DESCRIPTION  
       [0069]      FIG. 1  shows a perspective view of a tank  100  having a gauge assembly  110  according to the present disclosure.  FIG. 2  shows a perspective view of the gauge assembly  110 . It will be appreciated that the tank  100  is shown for exemplary purposes only and is in no way intended to limit the scope of the present disclosure.  
         [0070]     The gauge assembly  110  includes a port  120  that is accessible from outside the tank  100 . The port  120  allows fluid to be moved in and out of the tank  100 . The gauge assembly  110  also includes an indicator  130  for providing an indication of the fluid level in the tank  100 . In the present embodiment, the indicator  130  is a dial-type indicator, but any type of indicator could be used.  
         [0071]     As shown in  FIG. 2 , the gauge assembly  110  includes a stop-fill assembly  200 , a support member  190 , a vertical shaft  160  disposed within the support member  190 , a float  140  and a float arm  150 . The float  140  can be made of close foam material, and the vertical shaft  160 , the support member  190 , and the float arm  150  can be made of any rigid material, including an acetal such as Delrin®. A distal end of the float arm  150  is fixed to the float  140 , and a proximal end of the float arm  150  is connected to the vertical shaft  160  such that the float arm  150  is rotatable about the base of the vertical shaft  160 . As the fluid level in the tank  100  changes, the float  140  moves up or down with the fluid level causing the float arm  150  to rotate about the base of the support member  190 . The float arm  150  is shown in an alternate position in  FIG. 7 . Rotation of the float arm  150  about the base of the support member  190  causes the vertical shaft  160  to rotate about the longitudinal axis of the vertical shaft  160 . In the present embodiment, the rotation of the float arm  150  is translated to the rotation of the vertical shaft  160  by a sector gear  170 , fixed to the proximal end of the float arm  150 , that engages a pinion gear  180 , fixed to the lower end of the vertical shaft  160 .  
         [0072]     The stop-fill assembly  200  is fixed to an upper end of the support member  190 .  FIG. 3  shows a perspective view of the stop-fill assembly  200 , and  FIG. 4  shows an exploded view of the stop-fill assembly  200 . The stop-fill assembly  200  includes a valve body  210  (also shown in  FIG. 6 ), a valve head  220 , and a valve shuttle  230  (also shown in  FIG. 5 ), all of which can be made of any rigid material, including an acetal such as Delrin®.  
         [0073]     The valve shuttle  230  has a shuttle body  290  that serves as a blocking member for blocking fluid flow, an upper shaft  240  that extends upwardly from the shuttle body  290  through the valve head  220 , and a lower shaft  280  that extends downwardly from the shuttle body  290 . A magnet  270  that serves as an indicator driving member is fixed to an upper end of the upper shaft  240  for driving the indicator  130 . A tab  250  is formed in the lower end of the lower shaft  280  for engaging with a slot  260  (see  FIG. 8 ) formed in an upper end of the vertical shaft  160  in order to transmit rotary motion of the vertical shaft  160  to the valve shuttle  230 . As the vertical shaft  160  rotates, the magnet  270  also rotates. The magnet  160  is coupled with a dial  370  of the indicator  130  such that the rotation of the magnet  270  causes rotation of the dial  370  according to known methods. The lower shaft  280  also includes an opposing pair of release ribs  320  for engaging with an opposing pair of release slots  330  formed in the valve body  210  when the stop-fill assembly  200  is in a closed position.  
         [0074]     It is contemplated that an indicator other than the one used in the present embodiment can be used that does not require the presence of the magnet  270 . For example, an indicator driving member such as an encoded disk could be used in place of the magnet  270  and an indicator could be used that optically couples with the encoded disk to translate the rotational position of the encoded disk into a fluid level. In fact, it is contemplated that any kind of indicator and/or indicator driving member can be used that translates the rotation of the upper shaft  240  into a fluid level.  
         [0075]     The stop-fill assembly  200  includes an optional valve o-ring  300  for assisting in sealing the shuttle body  290  to a seal surface  310  of the valve body  210  when the stop-fill assembly is in the closed position. A seal  340  can optionally be provided for assisting in sealing the juncture between the valve head  220  and the valve body  210 . Depending on how the valve body  210  is attached to the valve head  220 , the seal  340  can be unnecessary, for example if the valve body  210  and valve head  220  are welded together, for example by ultrasonic welding. A spring retainer  350  is provided in a through-hole in the lower shaft  280  and extends from both sides of the lower shaft  280  in order to retain an upper end of a spring  360  (see  FIG. 8 ). It will be appreciated that, instead of using a separate item as the spring retainer  350 , the spring retainer  350  can instead be integrally formed in the valve shuttle  230 .  
         [0076]     The stop-fill assembly  200  can transition between an open position and a closed position. In the open position, fluid from the port  120  can flow through the stop-fill assembly  200 , while in the closed position fluid from the port  120  is prevented from flowing through the stop-fill assembly  200 . A top view of the stop-fill assembly  200  is provided in  FIGS. 9 and 13 , where  FIG. 9  shows a top view of the stop-fill assembly  200  when in the closed position, and  FIG. 13  shows a top view of the stop-fill assembly  200  when in the open position.  FIGS. 10 and 11  show cross-sectional views and  FIGS. 10A and 11A  show partial cross-sectional views of the closed position along section lines X-X and XI-XI, respectively, of  FIG. 9 , while  FIGS. 14 and 15  provide cross-sectional views of the open position along section lines XIV-XIV and XV-XV, respectively, of  FIG. 13 .  
         [0077]     In the open position, as shown in  FIGS. 14 and 15  and in  FIGS. 14A and 15A , and under the pressure of incoming fluid from the port  120  pressing downward on the shuttle body  290 , the release ribs  320  of the valve shuttle  230  ride against the upper surface of the valve body  210 . Thus, as best shown in  FIG. 14 , the release ribs  320  are what keep the stop-fill assembly  200  open against the force of a fluid flow from the port  120 . When the gauge assembly  110  is in the empty position (i.e., having the float arm  150  rotated to the position corresponding with an empty condition of the tank) the release ribs  320  are at 90 degree angles to the slots, sitting on the upper surface of the valve body  210  so that the valve shuttle  230  cannot go down. In this configuration, fluid from the port  120  travels downward through the space between the upper shaft  240  and the valve head  220 , around the shuttle body  290  across flow surfaces  380 ,  390 ,  395 , then through fill ports  410  en route to the inside of the tank  100 .  
         [0078]     As the vertical shaft  160  rotates due to the motion of the float arm  150 , the valve shuttle  230  rotates and eventually rotates to the position shown in  FIGS. 10 and 10 A and  FIGS. 11 and 11 A where the release ribs  320  line up with the release slots  330 , which is best shown in  FIG. 11 . When this happens, the downward pressure of the fluid flow, which is sufficient to overcome the opposing pressure of the spring  360 , causes the release ribs  320  to drop into the release slots  330  due to the force from the fluid flow. As shown in  FIGS. 10 and 12 , the shuttle body  290  acts as a blocking member since the contacting surfaces of the shuttle body  290  and the valve body  210  prevent fluid from traveling from the space above the shuttle body  290  to the fill ports  410  or into the tank  100 . The optional valve o-ring  300  assists in sealing the junction between the shuttle body  290  to the valve body  210 .  
         [0079]     Once the stop-fill assembly  200  is in the closed position, filling of the tank  100  is halted and at some point the source of the incoming fluid is disconnected from the port  120  or the port  120  is closed. At this point, since there is no longer any pressure against the upper side of the valve shuttle  230 , the valve shuttle  230  is moved upward under the force of the spring  360  so that the stop-fill assembly  200  transitions to the open position. This allows for fluid to exit the tank  100  by traveling back up through the stop-fill assembly  200  to the port  120 .  
         [0080]     In the present embodiment, the total rotation of the float arm  150  between full and empty fluid levels is approximately 100 degrees, while the total rotation necessary for moving the valve shuttle  230  between the open position and the closed position is pinion gear  180  is close to a one to one relationship. However, it will be appreciated that the angle of the range of motion of the float arm  150  can vary, for example based on the size and shape of the tank  100 , and the angle of the range of motion of the valve shuttle  230  can vary, for example based on the requirements of the indicator  130 . Thus the relationship between the sector gear  170  and the pinion gear  180  can vary so long as the relationship is such that it allows the angle of the range of motion of the float arm  150  and the angle of the range of motion of the valve shuttle  230  needed at the dial  370  of the indicator  130  to coincide.  
         [0081]     In some cases there may be relatively high pressures against the shuttle body  290  due to the filling pressure and the fluid flow. The actual flotation or the buoyancy of the float  140  produces a relatively small torque, so friction between the release ribs  320  and the upper surface of the valve body  210  might be high and resist rotation of the valve shuttle  230 . For this reason, it is desirable to keep the diameter of rotation of the release ribs  320  as small as practical to reduce the resisting torque. Since the torque felt by the valve shuttle  230  is tangential force times moment arm, reducing the moment arm (i.e., diameter of rotation of the release ribs  320 ) reduces the resisting friction torque. It is also desirable to form the valve shuttle  230 , particularly the release ribs  320 , and the valve body  210 , particularly the upper surface thereof, from a material having a low coefficient of friction against itself, for example an acetal such as Delrin®. Another option is to provide a friction-reducing material (not shown), for example a Teflon® fill material, between the release ribs  320  and the upper surface of the valve body  210 , that is made of a material having a low coefficient of friction.  
         [0082]     In addition, the flow surfaces  380  of the shuttle body  290  are slanted such that when fluid flows across the flow surface  380  the pressure of the fluid against the slanted surface will tend to rotate the valve shuttle  230  in a predetermined direction (clockwise in the present embodiment) to help overcome the friction between the release ribs  320  and the upper surface of the valve body  210 . Also, since fluid flow into the tank  100  across the slanted flow surfaces  380  will tend to rotate the valve shuttle  230  in a predetermined direction as the tank  100  is being filled, clearances are reduced or removed between portions of various parts, such as between portions of the tab  250  and the slot  260  and between portions of engaged teeth of the sector gear  170  and the pinion gear  180 , while the tank  100  is being filled. For example, the slot  260  can be slightly wider than the thickness of the tab  250  to allow for the tab  250  to be longitudinally inserted and removed from the slot  260 . As a consequence, the tab  250  would be free to rotate to some degree while inserted in the slot  260 . Therefore, if the valve shuttle  230  is not provided with a slanted surface such as flow surface  380 , turbulence from incoming fluid flowing across the valve shuttle  230  could cause unpredictable rotational motion of the valve shuttle  230 . However, since the fluid flow across flow surfaces  380  tends to rotate the valve shuttle  230  in a predetermined direction, the tab  250  will be rotated, in the predetermined direction, relative to the slot  260  at or near a maximum degree allowed by the total clearance between the tab  250  and the slot  260  such that portions of the tab  250  contact portions of the slot  260 . That is, a clearance is reduced or eliminated between portions of the tab  250  and the slot  260  as fluid is flowing into the tank  100 . It will be appreciated that a clearance between portions of teeth of the sector gear  170  and the pinion gear  180  is also reduced or eliminated since the rotation of the valve shuttle  130  is transferred to push together engaging teeth of the pinion gear  180  and the sector gear  170  as fluid is flowing into the tank  100 . Thus, with the slanted flow surface  380 , clearances between portions of various parts are reduced or eliminated allowing a greater degree of accuracy to be achieved in predicting the location of the release ribs  320  relative to the release slots  330  while the tank  100  is being filled.  
         [0083]     The shuttle and valve can be designed by considering control of the pressure zones through the flow path of the valve. The valve is preferably designed to create low pressure zones above the shuttle and high pressure zones below the shuttle. Such a design will tend to lessen the total downward force on the shuttle thus reducing the friction working against the desired rotation of the shuttle. The area of flow at various points along the flow path can be plotted and the pressure profile determined. Thus, the specific design of the chamber and the shuttle can be modified to change the pressure profile as desired.  
         [0084]     In the event that smooth slanted flow surfaces  380  are insufficient to provide the desired rotation force to valve shuttle  230  in a predetermined direction to help overcome the friction between the various portions of the valve shuttle which are in contact with the valve body, vanes can be provided on the valve shuttle of a predetermined shape and size to impart the desired rotational force to the valve shuttle in a predetermined direction. FIGS.  16 A-D illustrated various configuration of vanes, and FIGS.  17 A-D are end views of the respective figures in FIGS.  16 A-D. Any desired shape of the vanes can be utilized, and while all of the illustrated vanes extend from the surface of the shuttle, it will be appreciated that vanes could be supplied in the form of grooves in the shuttle.  FIGS. 16A and 17A  show vanes  400  having a uniform thickness and having a substantially flat front side surface  402  and a substantially flat rear side (not shown). Vanes  400  are set at a predetermined angle  406  to shuttle axis  408 .  FIGS. 16B and 17B  show vanes  411  in the shape of a curved plate of substantially uniform thickness and having a curved front side  412  and a curved rear side  414 . The front and rear sides can be oriented such that they are substantially parallel to the shuttle axis  408 .  FIGS. 16C and 17D  illustrate vanes  420  having a substantially uniform thickness and having a flat front side  422  and a flat rear side  424 . The vanes have a longitudinal axis  426  which is perpendicular to the shuttle axis  408  and set off the shuttle axis a predetermined distance  428 .  FIGS. 16D and 17D  illustrate vanes  430  having a substantially uniform cross-section and a curved front side  432  and a curved rear side  434 . The inner end  436  of vanes  432  is adjacent to the shuttle axis  408  and surfaces of the front and rear side  432  and  434  are parallel to axis  408 . While the vanes have been illustrated having substantially uniform thickness, it will be appreciated by those skilled in the art that they may have non-uniform thickness. The base where the vanes attach to the shuttle can be thicker than the other end. The flow of fluid across the vanes may assist in rotating the valve shuttle from the open position to the closed position. The vanes can be shaped such that the thickness of the vanes varies in the shape of an airfoil.  
         [0085]     The spring  360  allows for the stop-fill assembly  200  to remain in the open position when not under the pressure of incoming fluid. However, in some cases the pressure of fluid in the tank  100  is sufficient to cause the valve shuttle  230  to move to the open position when the port  120  is open so that even without the spring  360  fluid can be removed from the tank  100 .  
         [0086]     It is contemplated that an arrangement other than the above embodiment having the float arm  150  can be used in conjunction with other features disclosed herein. One option is to use a spiral gauge having a float on the vertical shaft  160  where the vertical shaft  160  has a ramp going up such that, as the float moves up and down the vertical shaft  160 , the shaft  160  rotates.  
         [0087]     It is also contemplated that the device could be modified to eliminate the indicator or the stop-fill function. For example, the valve shuttle  230  could be replaced with a shaft so that the gauge assembly drives the indicator  130  but does provide stop-fill functionality. As another example, the indicator  130  and magnet  270  could be eliminated so that the gauge assembly has stop-fill functionality but not an indicator.  
         [0088]     Referring now to  FIG. 18 , a side view of a combination service valve stop-fill assembly and liquid level indicator in accordance with additional aspects of the present disclosure is shown. As will be described, and as can be seen from  FIG. 18 , the combination  1800  shares many parts and features that have been previously described herein. A service valve assembly  1805  connects to a stop-fill assembly  1810 . A dial  1815  is also provided and interconnects with the service valve assembly  1805 . In some embodiments the dial may be removable and reattachable by the user, while in other embodiments the dial may be permanently or semi-permanently affixed to the service valve. The service valve assembly  1805  provides a port  120  in a valve outlet  1802 . The service valve assembly  1805  also provides port threads  1814 . The port threads  1814  may be used to interconnect the service valve assembly  1805  with an external device such as a filling device or appliance. A tank connection  1820  ( FIG. 20 ) is also provided for connecting with a tank such as the tank  100  shown in  FIG. 1 . To aid in connection to the tank, the tank connection  1820  may provide tank connection threads  1822 . In some embodiments, the threads  1822  will mate with threads provided on the tank  100 . Also shown in the embodiment of  FIG. 18  is a service valve knob  1812 . In some embodiments, the service valve knob  1812  may be used to allow or restrict the flow of gas through the service valve assembly  1805 .  
         [0089]     The stop-fill assembly  1810  is similar in many respects to the stop-fill devices that have been previously described herein. A support member  190  secures a rotatable vertical shaft  160  that attaches to a pinion gear  180 . The pinion gear  180  engages a sector gear  170  which attaches to a float arm  150 . As before, a float  140  is provided at one end of the float arm  150 . In the embodiment shown in  FIG. 18 a  counter balance  1825  is provided at the end of the float arm  150  opposite the float  140 . The counter balance  1825  may serve to decrease the resistance to movement that may be encountered internally in the stop-fill assembly  1810 . Additionally, as can be seen in  FIG. 18 , the counter-balance  1825  may serve to prevent an over rotation of the float arm  150  via its interference with the support member  190 .  
         [0090]     The vertical shaft  160  rotates in response to movement of the float  140 . The rotation of the vertical shaft  160  drives the fluid stopping mechanisms of the stop-fill assembly  1810 . Such mechanisms have been previously described with respect to other embodiments and therefore will not be repeated here. As will be shown in greater detail in subsequent drawings, the vertical shaft  160  also provides rotation of a magnet ( FIG. 19 ) that drives the gauge dial assembly  1815 .  
         [0091]     Referring now to  FIG. 19 , a side view of one embodiment of a stop-fill assembly suitable for use in a combination service valve stop-fill assembly is shown. The stop-fill assembly  1900  may be internally the same as those that have been previously described or it may be internally similar to those further described herein. In  FIG. 19  an upper shaft  240  can be seen connecting to a magnet  270 . A valve head  220  of the stop-fill assembly  1900  is provided with threads  1910 . The threads  1910  provide a secure means allowing the stop-fill assembly  1900  to connect with the lower service valve port  1820  of the service valve assembly  1805 .  
         [0092]     Referring now to  FIG. 20 , a perspective view of one embodiment of a service valve suitable for use in a combination service valve stop-fill is shown. In  FIG. 20  the service valve assembly  1805  is shown separated from the dial  1815  and the stop-fill assembly  1810 . Once again,  FIG. 20  illustrates the presence of the port  120  and tank connection  1820  which may be threaded with threads  1810  and  1822 , respectively. As before, the service valve knob  1812  may be provided to allow opening and closing of the service valve assembly  1805 . The service valve knob  1812  will typically sit atop the valve body  2020 . The valve body  2020  also connects to the valve outlet  1802 , the tank connection  1820 , and a pressure relief valve  2022 . With the dial  1815  removed, it can be seen that a set of wrench flats  2005  and  2205  ( FIG. 22A ) are provided on the service valve  1805  near the junction of the valve body  2020  and the tank connection  1820 . In the view of  FIG. 20 , one of these wrench flats  2005  can be seen. The wrench flat  2005  is shown with a recess  2010  provided therein. In one embodiment the service valve  1805  is a standard, commercially available brass service valve. In such a case, the recess  2010  can be machined directly into the wrench flat  2005 . Thus, with a relatively minor modification, a standard service valve  1805  can be adapted for use with aspects of the present disclosure. In some embodiments, the recess  2010  will be round but in other embodiments different shapes can be used. If a commercially available service valve is used, the depth of the recess  2010  relative to the wrench flat  2005  will be approximately 0.2 inches. As can be better appreciated from the drawings that follow, this will allow a dial magnet inserted sufficiently into the recess  2010  to interact with magnet  170  to provide readings on the gauge dial  1815 . In other embodiments, magnets  270  and  2152  ( FIG. 21B ) are sufficiently strong that a recess  2010  is not needed.  
         [0093]     Referring now to  FIG. 21A , a perspective view of the front side of one embodiment of a removable dial suitable for use in a combination service valve stop-fill apparatus in accordance with aspects of the present disclosure is shown. The dial  1815  provides a dial face  2110 . The dial face  2110  may be molded plastic or another suitable material. A lens  2115  may be provided. The lens  2115  may be glass or plastic or another suitably transparent material. It can be seen that the lens  2115  provides protection for the pointer  2130  as well as the indicator markings  2120 . The indicator markings  2120  may be painted or molded onto the dial face  2110 . In the embodiment of  FIG. 21A  markings corresponding to empty, half-full and full are shown but in other embodiments other markings may be used. It can be seen that the lens  2115  provides clearance for the pointer  2130  to sweep along the dial face  2110  to point to or near the corresponding indicator markings  2120 . The pointer  2130  is driven by an internal magnet  2152  ( FIG. 21B ). One or more spring clips  2140  may be seen protruding from the side of the gauge dial face  2110  opposite the pointer  2130 . In some embodiments, the spring clip  2140  may be provided to aid in alignment and/or attachment of the dial  1815  to the service valve assembly  1805 .  
         [0094]     Referring now to  FIG. 21B , a perspective view of the back side of one embodiment of a removable dial  1815  in accordance with aspects of the present disclosure is shown.  FIG. 21B  provides a view of the dial  1815  illustrating one possible placement of the spring clip  2140 . The spring clip  2140  may be attached to the backside of the dial face  2110  by a number of means including, but not limited to, snap fittings, friction fittings, gluing or molding. In one embodiment, the spring clip  2140  may be molded from the same plastic as the dial face  2110 . In other embodiments the spring clip  2140  may be another suitably resilient metal. Also protruding from the dial face  2110  on the backside is a dial magnet housing  2150 . The dial-magnet housing provides clearance and covering for the magnet  2152  that drives the pointer  2130 .  
         [0095]     Referring now to  FIGS. 22A and 22B , rear views with partial cutaways showing an upper portion of a combination service valve, stop-fill assembly, and removable dial in accordance with aspects of the present disclosure is shown. From the view of  FIG. 22A  it can be seen that the service valve assembly  1805  provides two wrench flats  2005  and  2205 . It can also be seen from this view that the wrench flats  2005  and  2205  may provide parallel flat surfaces. The wrench flats  2005  and  2205  may be used to aid in the insertion of the valve assembly  1805  into a tank such as the tank  100  of  FIG. 1 . The recess  2010  is also shown in dotted line within the wrench flat  2005 . A lower service valve throat  2210  is shown in outline and provides throat threads  2212 .  
         [0096]     From  FIG. 22A , it can be seen how the various components of the assembly combination of  FIGS. 22A and 22B  may be assembled. It can be seen that the dial  1815  may be attached to the service valve  1805  by inserting the dial magnet housing  2150  securely into the recess  2010  on the wrench flat  2005 . In some embodiments, the dial  1815  may be sufficiently secured to the service valve assembly  1805  by the friction between the dial magnet housing  2150  and the recess  2010 . In other embodiments, spring clips such as shown in  FIGS. 21A and 21B  may be used to stabilize and/or sufficiently secure the dial  1815  to the service valve assembly  1805 .  
         [0097]     It can also be seen that the magnet  270  attached to the end of the upper shaft  240  can be inserted into the lower service valve throat  2210 . In one embodiment, the threads  1910  of the valve head  220  may be adapted to interfit with the throat threads  2212  such that when the magnet  270  is inserted into the lower service valve throat  2210  as shown by the arrow B, the magnet  270  is in relatively close proximity to the magnet inside the dial magnet housing  2150 . Rotation of the magnet  270  about a generally vertical axis (i.e., the axis of rotation of shaft  240 ) causes variations of the associated flux field about the vertical axis. This flux field interacts with the flux field associated with the dial magnet  2152  to cause rotation of the dial magnet about a generally horizontal axis (i.e., the axis of rotation of the dial pointer  2130 ). Thus, a rotation of the magnet  270  translates into movement of the pointer  2130 . It can also be seen that the rotation of the shaft  240  and magnet  270  is substantially orthogonal to the direction of rotation of the dial pointer  2130 . Thus, the axes need not necessarily be horizontal and vertical.  
         [0098]      FIG. 22B  shows the assembled combination of the service valve assembly  1805 , the dial  1815 , and the stop-fill assembly  1810 . It can be seen that the dial  1815  is securely fastened to the service valve assembly  1805  by having had the dial magnet housing  2150  inserted into the recess  2010 . As can be seen in the cutaway, the magnet  270  is rotatable in close proximity to the dial magnet housing  2150 . As the magnet  270  rotates in response to movements of the float  140 , such movements may be indicated on the face of the dial  1815  via magnetic interaction between the magnet  270  and the magnet contained within the dial  1815 .  
         [0099]      FIG. 22C  is a cross section of a service valve  1805  modified for use with a removable dial in accordance with aspects of the present disclosure. The service valve  1805  in  FIG. 22C  is shown without the stop-fill assembly  1810 , dial  1815 , or knob  1812 . The placement of the lower service valve throat  2210  relative to the wrench flats  2005  and  2205  can be seen from this view. It can also be seen that the lower service valve throat  2210  extends into an interior chamber  2230  of the service valve  1805 . The interior chamber  2230  allows fluids and/or gases to pass from the port  120  to the lower service valve throat  2210 . The service valve  1805 , when fully assembled and operational, provides means that are known in the art for selectively allowing fluid and gaseous transfer from the port  120  through the lower service valve throat  2210 . In one embodiment, the primary modification to the service valve  1805  includes machining or drilling a recess  2010  into one of the wrench flats  2005 ,  2205 . In other embodiments, the recess  2010  could be cast directly into the service valve  1805 , or created by other means. In the embodiment shown, the recess  2010  is prepared in the wrench flat  2005 .  
         [0100]      FIG. 23  is a side view of another combination service valve, stop-fill assembly, and liquid level indicator in accordance with aspects of the present disclosure. The combination  2300  is similar to the combination  1800  ( FIG. 18 ) previously described. However, in place of the gauge dial  1815 , the combination  2300  provides a magnetic field sensor  2310 . The magnetic field sensor  2310  senses the intensity and direction of the magnetic field produced by the magnet  270  ( FIG. 19 ). In one embodiment, the magnetic field sensor will be a two pole analog magnetic sensor such as the TESLA3 from the Asahi Kasei Corporation of Osaka, Japan. The magnetic field sensor  2310  may convey data corresponding to the position of the magnet  270  to a remote location. The field sensor  2310  could convey data wirelessly or may convey data through one or more electrical leads  2313 , as shown. Two leads are shown but more or fewer could be used depending upon the field sensor  2310  being used.  
         [0101]     A dial or indicator  2320  may provided at a remote location for viewing information corresponding to the position of the magnet  270 . In one embodiment, the electrical signals provided wirelessly or via the leads  2313  will be processed into a liquid level reading such as a fuel level. Processing or signal conditioning may take place locally or remotely (e.g., at the sensor  2310  or at or near the indicator  2320 ). Although only a single reading is shown on the indicator  2320 , in some embodiments, the indicator  2320  will provide readouts from multiple locations or gauges. The readout on the indicator  2320  is shown in a digital format but could also be in an analog format, possibly similar in appearance to the gauge dial  1815  ( FIG. 18 ).  
         [0102]      FIG. 24A  is an exploded view of a stop-fill assembly in accordance with aspects of the present disclosure. The stop-fill assembly  1810  may be used in a combination device such as those shown in  FIGS. 18-19 . The stop-fill assembly  1810  is similar in some respects to the stop-fill assemblies previously described herein. A support member  190  is provided with a vertical shaft  160  disposed within. A float arm  150  is connected to the support member  190  so as to be able to rotate thereon. An eyelet  2316  may be provided as a fastener between the support member  190  and the float arm  150 . The float arm  150  is also connected at opposite ends to a float  140  and a counter balance  1825 . Rotation of the float arm  150  about the base of the support member  190  causes the vertical shaft  160  to rotate about the longitudinal axis of the vertical shaft  160 . The rotation of the float arm  150  may be translated to the rotation of the vertical shaft  160  by a sector gear  170 , fixed to the proximal end of the float arm  150  that engages a pinion gear  180 , fixed to the lower end of the vertical shaft  160 .  
         [0103]     The stop-fill assembly  1810  also includes a valve body  210  and a valve head  220 . A shuttle body  290  serves as a blocking member for blocking fluid flow. An upper shaft  240  extends upwardly from the shuttle body  290  through the valve head  220 . If desired, an eyelet  2311  may be provided for increasing the durability or structural integrity of the valve head  220 . A magnet,  270  that serves as an indicator driving member, is fixed to an upper end of the upper shaft  240 . A tab  250  is formed below the shuttle body  290  on a lower shaft  280 . The tab  250  interfits with the slot  260  of the vertical shaft  160  in order to transmit rotary motion of the vertical shaft  160  to the shuttle body  290 . The tab  250  may be free to slide vertically within the slot  260  such that the lower shaft  280  and connected shuttle body  290  can move vertically independent of the vertical shaft  160 . The lower shaft  280  also includes an opposing pair of release ribs  320  for engaging with an opposing pair of release slots  330  formed in the valve body  210  when the stop-fill assembly  200  is in a closed position. A bearing clip  2314  may be provided between the valve body  210  and the release ribs  320  to increase the durability and decrease the friction of the contact between the release ribs and the valve body. The bearing clip  2314  may be composed of a metal, a low friction plastic, a polymer, or other substance.  
         [0104]     The stop-fill assembly  1810  can transition between an open position and a closed position. In the open position, fluid (e.g., from the port  120 ) can flow through the stop-fill assembly  1810 , while in the closed position fluid is prevented from flowing through the stop-fill assembly  1810 .  
         [0105]     In the open position, and under the pressure of incoming fluid pressing downward on the shuttle body  290 , the release ribs  320  of the valve shuttle  230  ride against the upper surface of the valve body  210  or the bearing clip  2314 . Thus, the release ribs  320  keep the stop-fill assembly  200  open against the force of a fluid flow (e.g., from the port  120 ). When the float arm  150  is rotated to the position corresponding with an empty condition, the release ribs  320  are at 90 degree angles to the slots  330 , sitting on the upper surface of the valve body  210  so that the valve shuttle body  290  cannot go down. In this configuration, fluid travels downward through the space between the upper shaft  240  and the valve head  220 , around the shuttle body  290 , through fill ports  410  and out through ports  2340  formed through the sides of valve body  210 .  
         [0106]      FIG. 24B  is a partial top view of the valve body  210  of  FIG. 24A  with release ribs  320  at 90 degree angles to slots  330 , sitting on the surface of valve body  210  (and bearing  2314 ) so that the valve shuttle body is in the open position.  FIG. 24C  is a partial sectional and partial cutaway view of the shuttle body  290  engaged in the valve body of  FIG. 24A . In the open position, fluid travels downward through the space between the upper shaft  240  and the valve head  220 , around the shuttle body  290  and through discharge ports  2340  formed in valve body  210  and into the container (e.g., tank  100 ). In this variation, ports  2340  direct fluid entering tank  100  through the stop-fill device  1800  radially away from a central longitudinal axis of tank and likewise away from shaft  160 . Discharging fluids through radially directed ports  2340  reduces the amount of turbulence generated in tank  100  during the filling operation along with possible impingment of the fluid onto float  140  or float arm  150  which can interfere with the operation of the float.  
         [0107]     As the vertical shaft  160  rotates due to the motion of the float arm  150 , the shuttle body  190  rotates and eventually rotates to the closed position. When this happens, the downward pressure of the fluid flow, which is sufficient to overcome the opposing pressure of the spring  360 , causes the release ribs  320  to drop through the bearing clip  2314  and into the release slots  330 . The shuttle body  290  then acts as a blocking member. As shown in  FIG. 24C , a beveled circumferential surface  2342  of shuttle body  290  seats against a corresponding beveled surface or seat  2344  of valve body  210  to block the flow of fluid through the stop-fill assembly  1810 . Notably, the movement of shuttle body when release ribs  320  move into alignment with release slots  330  is longitudinally independent of the rotation of vertical shaft  160 . In other words, the shuttle body  290  can move up and down in the longitudinal direction even though the vertical shaft  160  is fixed in the longitudinal direction, while at the same time the shuttle body remains rotationally engaged with the vertical shaft such that the shuttle body and vertical shaft always rotate together. Thus, shuttle body  290  rotates in response to the rotation of shaft  160 , but translates longitudinally independent of shaft  160  when moving between the open and closed positions.  
         [0108]     In the embodiment shown, a separate spring clip  2312  ( FIG. 24A ) is provided for stabilizing the spring  360  against the valve body  210  and for preventing binding of the spring when the vertical shaft  160  rotates. The relatively short distance that the shuttle body  290  travels when moving into the closed position means that the vertical translation of the magnet  270  is also relatively small. Therefore the magnetic field produced by the magnet  270  does not change substantially, and thus the movement of the magnet  270  along the axis of the stop-fill assembly  1810  has no substantial bearing on the interaction of the magnet  270  and the pointer magnet  2152 . It is the rotational movement of the magnet  270  that produces a change in the magnetic flux field that may be recognizable by the dial  1815  as a change in the fluid level of the tank  100 .  
         [0109]     Once the stop-fill assembly  1810  is in the closed position, filling is halted. The source of the incoming fluid is disconnected from the port  120  or the port  120  is closed. At this point, since there is no longer any pressure against the upper side of the valve shuttle body  290 , the valve shuttle body  290  is moved upward under the force of the spring  360  so that the stop-fill assembly  1810  transitions to the open position. This allows for fluid or gas to exit the tank  100  by traveling back up through the stop-fill assembly  1810  to the port  120 .  
         [0110]     In some cases there may be relatively high pressures against the shuttle body  290  due to the filling pressure and the fluid flow. The actual flotation or the buoyancy of the float  140  produces a relatively small torque, so friction between the release ribs  320  and the upper surface of the valve body  210  might be high and resist rotation of the shuttle body  290 . For this reason, as has been described, low fiction materials may be selected for the construction of the release ribs  320 , valve body  210 , and other components. Furthermore a bearing clip  2314  may be employed to both decrease friction and increase durability. Additionally, flow surfaces may be provided on the shuttle body  290  such that pressure of the incoming fluid assists in the rotation of the valve shuttle body  290 . As has been described, the shape of the shuttle body  290  may be chosen such as to assist in its own rotation.  
         [0111]      FIG. 24D  is a top view of an alternate valve body  2350  and  FIG. 24E  is a partial cutaway and partial sectional view of a corresponding shuttle body  2352 . In this variation, release ribs  320  have been replaced with a pair of release arms  2354  that extend outward from an upper surface of shuttle body  2352  and downward to a surface  2356  of valve body  2350  outside of beveled valve seat  2344 . A pair of release apertures  2358  formed in surface  2356  receive the distal ends  2360  of arms  2354 , permitting the shuttle body to move downward when arms  2354  are moved into alignment with apertures  2358 .  
         [0112]     In the open position, ends  2360  of arms  2354  rest on surface  2356 , holding shuttle body  2352  up so that fluid may past the shuttle body through fill ports  410  and into tank  100  through radially directed discharge ports  2340 . As the vertical shaft  160  rotates due to the motion of the float arm  150 , the shuttle body  2352  rotates and eventually rotates to the closed position. When this happens, the downward pressure of the fluid flow, which is sufficient to overcome the opposing pressure of the spring  360 , causes the ends  2360  of release arms  2354  to drop into release apertures  2358 . Shuttle body  2352  moves down with beveled circumferential surface  2342  of shuttle body  2352  seating against the corresponding beveled surface  2344  of valve body  2350  to block the flow of fluid through the stop-fill assembly  1810 .  
         [0113]      FIG. 24F  is a side view of an alternate float assembly  2380  for use with stop-fill assembly  1810 . Float assembly  2380  includes a float arm  2382 , a float  2384  attached to a first end of arm  2382  and a counterweight or counterbalance  2386  attached to a second end of arm  2382 . Float arm  2382  is operatively connected to a sector gear  170  which drives pinion gear  180  that is attached to vertical shaft  160 .  
         [0114]     In the embodiment illustrated in  FIG. 24F , float  2384  is mounted on arm  2382  such that the float is offset from the longitudinal axis of the float arm such that a longitudinal axis of the float extends below the float arm when the float arm is in a horizontal orientation. In one embodiment, float  2384  is slanted downward at an angle α from about 10 degrees to about 45 degrees relative to a longitudinal axis  2388  of arm  2382 . It was found that angling float  2384  relative to the longitudinal axis of arm  2382  in this manner improved the efficiency of the float and increased the sensitivity of the assembly to changes in liquid level in tank  100  at near full volumes or at volumes where the angle of the longitudinal axis  2388  of arm  2382  relative to horizontal approaches 90 degrees. In another variation, float  2384  may be offset from the longitudinal axis of arm  2384  by forming a bend in the arm adjacent to the float, offsetting the float on the arm or using an extension of the arm that offsets the float.  
         [0115]      FIG. 24G  is a partial sectional view illustrating the stop-fill assembly  1810  of  FIG. 24A  positioned in pressurized tank  100 . As illustrated tank  100  includes a cylindrical sidewall  102  defining a central axis  104  extending therethrough, a generally semi-cylindrical top wall  106 , a generally semi-cylindrical bottom wall  108  and a shield  112  extending at least partially around a service valve  2700  suitable for use in connection with stop-fill devices described herein. In one embodiment, service valve  2700  includes a valve inlet/outlet  1802  through which tank  100  is filled and emptied, a relief valve  2022 , and a threaded tank connection  1820  that is screwed into a threaded opening  122  in top wall  106  of the tank. Typically, tank  100  will have only one such opening  122  through which the tank is filled and emptied. Since tank  100  is filled and emptied through opening  122 , stop-fill assembly  1810  must function as a two way valve as described herein.  
         [0116]     Referring still to  FIG. 24G , a handle  1812  is provided for opening and closing service valve  2700 . Tank  100  is suitable for containing a pressurized fluid  114  such as liquefied natural gas (LNG), liquefied propane and/butane and similar volatile liquefied gases commonly used for cooking and heating. Tank  100  may be filled with such liquefied gases through service valve  2700  and stop-fill assembly  1810  which blocks flow of the liquefied gas when the amount of fluid  114  reaches a predetermined level corresponding to a desired volume of pressurized fluid  114  in tank  100  and then reopens when the fill source is disconnected and pressure across the stop-fill assembly is equalized such that spring  360  ( FIG. 19A ) forces shuttle body  290  upwardly, opening the stop-fill assembly. Gases  116  vaporized from pressurized fluid  114  are released through service valve  2700  which is typically connected to a gas grill, stove, heater or similar device with suitable tubing or pipe.  
         [0117]     In the illustrated embodiment, pressurized fluid  114  entering tank  100  flows through radially directed ports  2340  which direct fluid entering the tank away from longitudinal axis  104  of tank  100  in the direction of arrows  124 . In this manner, the amount of turbulence generated on the surface of the fluid  114  in tank  100  during the filling operation is reduced. Possible direct impingement of fluid  114  onto float  140 , float arm  150  and/or counter balance  1825  is eliminated or substantially reduced. Reducing surface turbulence and/or impingement on the float arm reduces the likelihood of premature activation of the stop-fill device, which could result in incomplete filling.  
         [0118]      FIG. 25  is a diagram illustrating one possible correlation between the magnetic field produced by an indicator magnet and a dial reading according to aspects of the present disclosure. Relative field intensities (in both N and S) and directions correspondent to degrees of rotation of the magnet  270  from a starting point are labeled for illustration. Referring also back to  FIGS. 19 and 24 , it can be seen that the orientation of the magnet  270  changes in response to a level of the float  140  on the float arm  150 . The magnet  270  will have a north pole and a south pole and will produce a magnetic field in proximity thereto that will vary in strength and direction. The float arm  150  and pinion gear  180  can be configured to provide a rotation of the magnet  270  starting from a known position (e.g., empty) and proceeding to another known position (e.g., full) in a known ratio. Thus the magnetic field direction and strength produced by the magnet  270  as it takes on various propositions between open and closed can be known and used to calibrate a dial  1815  or magnetic field sensor  2310 . The diagram of  FIG. 25  illustrates that in one embodiment, only a portion of the field strengths and directions possible from the magnet  270  may be used in order to simplify calibration and readings. The direction (e.g., north or south) and relative field strength produced in known location near the magnet  270  as it is rotated in graphed. It can be seen that within particular range R, the magnetic field strength and direction takes on each possible value or a subset of possible values only once. By selection of the gearing ratio of the gears  170  and  180  and the size and shape of the float art  150  and float  140 , the range R, or in the present embodiment, subset thereof, G, may be used over the range of possible fluid levels in the container (e.g., tank  100 ). Possible markings for a gauge dial or other indicator corresponding to the field values over the range G are shown in  FIG. 25  for illustration.  
         [0119]     Referring now to  FIG. 26 , a side view  2900  of the spatial relationship between a gauge magnet and a dial magnet according to aspects of the present disclosure is shown. The diagram  2900  could correspond to the relationship between the magnet  270  and the pointer magnet  2152  when in use with any of the gauge and dial combinations described herein, whether a stop-fill device is included in the combination or not. It can be seen that the magnet  270  attached to the upper shaft  240  and rotates about the axis  2910  of the shaft  240 . As the magnet  270  rotates, a plane  2912  is defined. In the two-dimensional view of  FIG. 29 , the plane  2912  is represented in dotted line. As has been described, a rotation of the magnet  270  about its axis  2910  causes a corresponding rotation of the pointer magnet  2152  about its axis  2914 . It can be seen here that the axes  2910  and  2914  are generally orthogonal. In some embodiments or applications, one axis will be vertical while the other is horizontal but this is not required. However, in some embodiments, an offset between the plane of rotation  2912  of the magnet  270  and the axis  2914  of rotation of the pointer magnet  2152  will be provided. This allows increased leverage in the magnetic flux between the magnets  270  and  2152  to ensure adequate rotation of the pointer magnet  2152  by the magnet  270 . The offset can vary by application and depending upon the range of motion needed in the pointer  2130 . The offset could also be in either direction i.e., above or below the axis  2914  along the shaft axis  2910 .  
         [0120]      FIG. 27  is a partial section, partial cut-away view of a combination gauge and stop-fill valve assembly  3000  suitable for use with a tank such as tank  100  ( FIG. 24G ) containing a pressurized fluid such as liquefied natural gas (LNG), liquefied propane and/butane and similar volatile liquefied gases commonly used for cooking and heating. Stop-fill valve assembly  3000  includes a valve body  3002  and a valve head  3004  configured to extend into the lower throat  3006  of a service valve  3008 . Valve head  3004  and throat  3006  may be provided with threads (not shown) for connecting stop-fill assembly  3000  to the service valve. A support member  3010  extends downwardly from valve body  3002  with a vertical shaft  3012  rotatably disposed within the support member. A float arm  3014  is connected to the distal end of support member  3010  for rotation about the distal end of the support member in response to changes in the fluid level in tank  100 .  
         [0121]     A float  3016  is connected to a first end of float arm  3014  with a counterbalance  3018  attached to a second end of the float arm remote from the float. Float  3016  moves in response to changes in the fluid level in tank  100 , causing float arm  3014  to rotate around the distal end of support member  3010 . Rotation of float arm  3014  is transmitted to vertical shaft  3012  by means of a sector gear  3022  attached to the float arm that engages a pinion gear  3024  mounted on the distal end of vertical shaft  3012  to rotate the shaft. The upper or proximate end of vertical shaft  3012  engages valve shuttle  3026 , e.g., by means of the tab-and-slot arrangement shown in  FIG. 24A , to rotate the shuttle in response to changes in the fluid level in tank  100 .  
         [0122]     As best illustrated in  FIGS. 27A and 27B , valve body  3002  includes fill ports  3020  that communicate with radial ports  3076  to allow fluid to flow into and out of tank  100 . In one variation, radial ports  3076  are directed radially away from and generally perpendicular to the longitudinal axis of support member  3010  to direct fluid entering tank  100  away from float  3016 , float arm  3014  or counterbalance  3018 . The radial orientation of ports  3076  prevents or minimizes impingement of fluid entering tank  100  on float  3016 , float arm  3014  or counterbalance  3018  and/or turbulence that may interfere with the operation of stop-fill assembly  3000 .  
         [0123]     Referring to  FIGS. 28 and 31 , valve shuttle  3026  includes an upper shaft  3028  with a magnet holder  3031  formed on the distal end of the upper shaft, a shuttle body  3032  and a lower shaft  3034 . Upper and lower shafts  3028 ,  3034  each extend along a longitudinal axis  3036  of valve shuttle  3026 . Shuttle body  3032  includes a generally conical upper wall  3033  with a plurality of ribs  3038  extending outwardly from the upper wall. A pair of release ribs  3030  extend radially outward from the proximate end of lower shaft  3034  and downwardly from shuttle body  3032 . Release ribs  3030  bear against valve body  3002  to support valve shuttle  3026  when stop-fill assembly  3000  is in the open position. A tab  3040  formed at the distal end of lower shaft  3034  engages a corresponding slot  3042  formed in the upper end of vertical shaft  3012  to transmit rotation (but not vertical motion) of the vertical shaft to valve shuttle  3026 . A spring  3044  disposed around the proximate end of vertical shaft  3012  biases valve shuttle  3026  upwardly away from the vertical shaft. A spring clip  3046  prevents spring  3044  from binding as vertical shaft  3012  and shuttle body  3032  rotate.  
         [0124]     As best illustrated in  FIG. 28  valve shuttle  3026  is disposed on valve body  3002  with upper shaft  3028  positioned in valve head  3004 . Shuttle body  3032  is positioned inside a valve chamber  3048  including an upper, generally conical wall  3050 , a cylindrical side wall  3052  and a bottom wall  3054 . In one variation, ribs  3038  act as stops, limiting upward travel of shuttle body  3032  in valve chamber  3048  by contacting conical wall  3050  of the chamber. As best illustrated in  FIG. 33 , a passage  3056  formed through bottom wall  3054  has opposed release slots  3058  extending therefrom for receiving release ribs  3030  when valve shuttle  3026  rotates to a position where the release ribs are aligned with the release slots. Lower shaft  3034  extends through a central portion of passage  3056  to engage the proximate end of vertical shaft  3012 . A beveled sealing surface or valve seat  3060  formed in bottom wall  3054  seals against a corresponding beveled sealing surface  3062  ( FIG. 31 ) that extends circumferentially around the lower edge of shuttle body  3032  when shuttle body  3032  translates into the closed position. In one variation, the distance between valve seat  3060  and sealing surface  3062  when stop-fill assembly  3000  is in the open position may be determined by the length of release ribs  3030  that support valve shuttle  3026 .  
         [0125]     Referring to  FIGS. 27 and 28 , stop-fill assembly  3000  operates in essentially the same manner as described in connection with embodiments disclosed above. Service valve  3008  is connected to a source of LNG or LPG and opened. The LPG flows through service valve  3008  into an annular space  3064  between valve head  3004  and upper shaft  3028  and into valve chamber  3048 . The LPG flows around shuttle body  3032 , between valve seat  3060  and sealing surface  3062  and through fill ports  3020 , discharging into tank  100  through radial ports  3076 . As tank  100  fills, lifting float  3016 , float arm  3014  rotates around the distal end of support member  3010 . Sector gear  3022  rotates with float arm  3014 , turning pinion gear  3024  and vertical shaft  3012 . Valve shuttle  3026  rotates with vertical shaft  3012  until release ribs  3030  move into alignment with release slots  3058 . When release ribs  3030  are aligned with release slots  3058 , the downward force on valve shuttle  3026  exerted by LPG flowing over shuttle body  3032  overcomes the biasing force of spring  3044 , causing the shuttle to translate longitudinally with the release ribs entering the release slots. Sealing surface  3062  of shuttle body  3026  moves into abutment with valve seat  3060 , closing off the flow of LPG through stop-fill assembly  3000 . When service valve  3008  is closed and/or the downward force on valve shuttle  3026  removed, spring  3044  pushes the valve shuttle up, returning the valve to the open position.  
         [0126]     Stop-fill valve  3000  relies on the force exerted on valve shuttle  3026  to close the valve when a fluid in the tank such as LNG or LPG reaches a predetermined level, for example 80% of the capacity of the tank. The force applied to valve shuttle  3026  is therefore dependent upon the rate of fluid flow and the differential pressure across the valve. However, LPG is a volatile material having a vapor pressure that varies considerably with temperature. For example the vapor pressure of 100% propane varies from 24.5 psig at 0 degrees F. to approximately 177 psig at 100 degrees F. Consequently, the pressure differential across stop-fill valve  3000  when filling tank  100  with LPG may vary considerably depending upon factors such as ambient temperature, pump pressure and the composition of the LPG (e.g., % propane). In view of these variations, it is desirable that stop-fill valve  3000  close quickly and reliably at relatively low differential pressures across the valve.  
         [0127]     Referring now to  FIGS. 29, 30  and  33 , in one variation, stop-fill valve  3000  is configured with a maximum upper flow area  3070  when the valve is in the open position. As best illustrated in  FIG. 30 , upper flow area  3070  is the cross-sectional area between conical upper wall  3033  of shuttle body  3032  and conical wall  3050  of valve chamber  3048  taken along line  30 - 30  of  FIG. 28 . As illustrated in  FIG. 29 , a lower flow area  3072  is the area between valve seat  3060  of valve body  3002  and the corresponding sealing surface  3062  of shuttle body  3032  when the valve is in the open position. The size of lower flow area  3072  may be increased or decreased by adjusting the length of release ribs  3030  which support valve shuttle  3026  when stop-fill valve  3000  is in the open position. Referring to  FIG. 32 , a swept surface area  3074  corresponds to the surface area of the conical upper wall  3033  of shuttle body  3032 .  
         [0128]     It was found that restricting the flow through between shuttle body  3032  and valve seat  3060  by reducing the area of lower flow area  3072  increased the speed at which the valve closed. For example, it was determined that reducing lower flow area  3072  from 0.065 square inches to 0.0445 square inches, a thirty two percent reduction, significantly increased the speed at which the valve closed when tested with water at a differential pressure of about 10 psig. In this example, upper flow area  3070  was increased from about 0.122 square inches to 0.1305 square inches, a seven percent increase and the swept surface area decreased from 0.086 square inches to 0.079 square inches, a decrease of about nine percent.  
         [0129]     Thus, in one variation, the ratio of the upper flow area  3070  to the lower flow area  3072  is approximately 1.8 to about 3.5 with the ratio of the swept surface  3074  to the lower flow area  3072  ranging from about 1.3 to about 2.5. In a preferred variation, the ratio of the upper flow area  3070  to the lower flow area  3072  is approximately 2.5 to about 3.0 with the ratio of the swept surface  3074  to the lower flow area  3072  ranging from about 1.5 to about 2.0. Most preferably, the ratio of the upper flow area  3070  to the lower flow area  3072  is approximately 2.9 with the ratio of the swept surface area  3074  to the lower flow area  3072  approximately 1.8.  
         [0130]     The drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to limit the following claims to the particular forms and examples disclosed. On the contrary, further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments will be apparent to those of ordinary skill in the art. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.

Technology Classification (CPC): 8