Patent Publication Number: US-8539991-B1

Title: Vapor recovery fuel dispensing nozzle

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a vapor recovery fuel dispensing nozzle of the general type disclosed in U.S. Pat. No. 5,289,856 and U.S. Pat. No. 5,255,723, the disclosures of which are herein incorporated by reference. These nozzles have vapor return valves within the nozzle bodies and responsive to fuel supply within the nozzle. Other forms of vapor recovery fuel dispensing nozzles of the balanced-type where fuel vapors are displaced from the vehicle fuel tank back into the underground tank, are disclosed in U.S. Pat. Nos. 4,697,624, 5,655,576, 6,951,229, and 7,082,972. In such a fuel dispensing nozzle assembly, a collapsible corrugated rubber bellows surrounds a fuel supply spout and defines therebetween a vapor return passage connected to a vapor return passage within the nozzle body and within a co-axial fuel supply hose. When a nozzle spout is inserted into a fuel fill tube or pipe projecting from a fuel tank of a motor vehicle, an annular vapor seal carried by the bellows engages the lip of the fill pipe. In some nozzles, as the bellows is axially compressed by further pressure on the nozzle, a valve within the vapor passage opens. Axial compression of the bellows may also actuate a diaphragm operated ball clutch which locks an axially movable stem to the nozzle body to form a fixed pivot support for a hand actuated lever connected to control a valve within the fuel supply passage. 
     When the annular resilient vapor seal of a vacuum assist nozzle engages the fuel fill pipe on a vehicle, it is desirable to obtain and maintain a positive annular pressure seal between the resilient vapor seal and the fill pipe to assure that surrounding air is not sucked into the nozzle and that fuel vapors in the fuel tank transfer with minimal resistance through the vapor return passage within the nozzle. In addition, when a vacuum-assist nozzle engages a fuel fill pipe on a vehicle having an on-board refueling vapor recovery (ORVR) system, it is desirable for the nozzle to sense when there is no significant flow of return vapor through the nozzle so that a vapor return valve in the nozzle will restrict or stop the flow of vapor back into the underground fuel tank. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to an improved vapor recovery fuel dispensing nozzle which provides the above desirable features of a vapor return valve which senses return vapor flow and avoids using a spring and/or a diaphragm which degrade over a period of use of the nozzle. A nozzle vapor return valve constructed in accordance with the invention also provides a consistent force for closing the vapor return valve over the life of the nozzle. In accordance with the invention, a fuel dispensing nozzle incorporates a magnetically controlled vapor return valve which is normally closed but moves to a fully open position in response to sensing the low pressure differential of a flow of return vapors within the vapor return passage so that the return flow of vapors is not restricted. 
     In accordance with the illustrated embodiment of the invention, a vapor valve incorporates a circular magnetically attractable disc of a ferrous material, and the disc is supported by retainers for axial movement in response to vapor flow from a lower closed position resting on an annular plastic seat member and an upper open position engaging the plastic retainers. The retainers also support a circular permanent magnet space below the disc and which normally holds the disc in its closed position seated on the annular seat member. When the vacuum-assist nozzle is dispensing fuel, the return vapor flow shifts the disc from its closed position to a fully open position to minimize any restriction to the return vapor flow. When the nozzle is dispensing fuel into the tank on a vehicle equipped with an ORVR system, the disc remains in its closed position so that the vapors are collected in the canister of the ORVR system. However, if the ORVR system is unable to retain all of the fuel vapors in the canister on the vehicle, the excess vapors which flow back into the nozzle are sufficient to move the disc upwardly to its open position so that the vapors may return to the underground storage tank. 
     Other features and advantages of the invention will be apparent from the following description, the accompanying drawings and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a vertical section of a vacuum-assist fuel dispensing nozzle enclosing a vapor flow responsive valve constructed in accordance with the invention; 
         FIG. 2  is an enlarged vertical section of the vapor flow responsive valve shown in the circle  2  of  FIG. 1 ; and 
         FIG. 3  is an exploded perspective view of the components of the vapor flow responsive valve shown in section in  FIG. 2 . 
     
    
    
     DESCRIPTION OF THE ILLUSTRATED EMBODIMENT 
       FIG. 1  shows a vacuum-assist vapor recovery fuel dispensing nozzle assembly or nozzle  10  which includes a cast aluminum body  12  having a tubular handle portion  14  and an annular or cylindrical outlet portion  16 . The body  12  defines an internal fuel supply passage  18 , and a fuel flow control valve  22  controls the flow of fuel through the passage  18  in response to pivoting of a manually actuated control lever  24  about a pivot pin  26 . The control valve  22  includes a valve member  28  within an annular seat member  29 . The valve member  28  is normally closed by a compression spring  31 , a spring support and a resilient washer confined by a cup-shaped plug  33  threaded into the body  12 . A rod or stem  34  extends from the valve member  28  and engages the control lever  24 , and a resilient O-ring surrounds the stem  34  and is retained within a plastic guide bushing  38  secured by a retaining ring and sealed to the body by a resilient O-ring. The control lever  24  is enclosed within a plastic lever guard  41  which is secured to the body  12  by a pair of cross pins  43 . A spring biased lever  46  is connected to the actuating lever  24 , and a plate  48  has a series of ribs for selectively receiving the end of the lever  46 , in a conventional manner, when the valve control lever  24  is gripped and moved upwardly to open the fuel valve  22 . 
     The body  12  also defines an internal vapor return passage  55  which extends within the fuel passage  18  within the handle portion  14 . The vapor return passage  55  extends from an inner end portion  61  which receives a tubular fitting secured to one end of a flexible co-axial fuel supply and vapor return hose (not shown). The return flow of vapor through the return passage  55  is controlled by a metal or brass valve member  64  which is mounted on and sealed to the actuating stem  34  and carries a resilient O-ring which normally engages a tapered or frusto-conical seat  66  within the valve body. When the rod or stem  34  is moved upwardly in response to pivoting the lever  24 , both the fuel supply valve member  28  and the vapor return valve member  64  move from their corresponding closed positions (FIG.  1 ) to their open positions and return to their closed positions when the control lever  24  returns to its released position ( FIG. 1 ). 
     The forward end portion of the actuating lever  24  is pivotally supported by the lower end portion of a molded plastic tube or tubular member  70  which receives the pivot pin  26 . The tubular member  70  is biased upwardly by a compression spring  72 , and an enlarged upper end portion of the member  70  is locked to the nozzle body or released from the nozzle body by actuation of a ball clutch  74  forming part of an automatic shut-off mechanism  75 . As generally disclosed in the above-mentioned U.S. Pat. No. 5,255,723, the mechanism  75  includes a flexible diaphragm  78  secured to a clutch stem  81  which is normally biased downwardly by a compression spring retained within a cap member  85  secured to the nozzle body. A set of balls  87  surround the clutch stem  81  and are retained within corresponding holes within the enlarged upper end portion of the tubular member  70  when the diaphragm is in its normal position shown in  FIG. 1 . In this position, the balls  87  are cammed outwardly by the stem  81  above an annular tapered shoulder within the body to lock the tubular member  70  to the body and thereby fix the pivot pin  26 . 
     The forward end portion  16  of the nozzle body receives a fitting  92  which is retained by a screw  93  and supports a spring biased fuel control poppet valve  95  within the fuel supply passage  18 . The poppet valve  95  operates in a manner as disclosed in above-mentioned &#39;723 patent. The forward end portion  16  of the nozzle body also supports a rigid or metal fuel supply tube or spout  130  which has an inner end portion secured to a fitting  132  confined within the end portion  16  of the nozzle body contacting the fitting  92 . The outer end portion of the spout  130  is adapted to project into a fuel inlet fill pipe or tube (not shown) projecting upwardly from a motor vehicle fuel tank. A collar  136  is secured to the spout  130  and is adapted to engage an inwardly projecting annular rib formed on the fill tube to secure the spout  130  to the fill tube and prevent it from sliding outwardly from the fill tube after the spout  130  is initially inserted into the fill tube. An overfill shut off air bleed passage  144  extends longitudinally within the spout  130  and has an inner end portion connected to a passage  146 . The function of the air bleed passage  144  is the same as described in the &#39;723 patent. 
     The forwarding portion  16  of the body  12  also supports a flexible corrugated compressible bellows  150  which encloses an annular compression spring  152 . The spring  152  and bellows connect the forward end portion  16  to an annular cup member  155  which retains a resilient annular seal or gasket  157 . When the nozzle  10  is used for dispensing fuel, the spout  130  is extended into the inlet tube (not shown) extending from a fuel receiving tank, and the gasket  157  engages the outer end of the fill tube with sufficient force to collapse the spring  152  and bellows  150  and form a seal between the gasket  157  and the fill tube and form a continuation of the vapor return passage  55 . 
     In accordance with the present invention, the body  12  supports a vapor flow responsive control valve  160  ( FIGS. 1 &amp; 2 ) within the vapor return passage  55 . After the valve is assembled, the valve  160  slides into a cylindrical bore  162  ( FIG. 2 ) formed within the body  12  and is secured by a spring retaining ring  163 . The valve  160  is inserted into the bore  162  through an aligned opening in the valve body and closed by a sealed disc  164 . The valve  160  senses the low pressure return vapor flow within the vapor passage  55 , and if there is no flow, the valve closes. When the valve  160  senses a return vapor flow, the valve opens fully and presents no restriction to the return vapor flow. 
     As shown in  FIGS. 2 and 3 , the valve  160  preferably includes a first magnetic valve member in the form of a flat circular disc  166  of a ferrous sheet metal. The disc  166  normally seats on an annular seat member  168  formed or molded of a plastics material such as an acetyl material. The annular seat  168  is supported within the bore  162  by four peripherally spaced molded plastic retainers  170 , and the seat member  168  and retainers  170  have mating and interfitting notches  171  and  172  which position and lock the seat member  168  within the bore  162 . The base portion of each retainer  170  also has a slot or groove  174  which cooperates to support a second magnetic valve member in the form of a circular permanent magnet  176 . The magnet  176  is spaced below the seat  168  and provides a sufficient magnetic force or attraction to the disc  166  for normally holding the disc against the top surface of the seat  168 , as shown in  FIG. 2 . When return vapor flows within the passage  55 , the vapor flows upwardly around the magnet  176  and between the retainers  170  to press upwardly on the disc  166  and lift it from the seat  168 . With only a light vapor flow, the disc  166  moves upwardly to a fully open position where it stops against the inwardly projecting stops or projections  178  on the retainers  170 , as shown by the dotted position in  FIG. 2 . In this open position, the vapor is free to flow through the valve  160  and through the vapor return passage  55  without any significant restriction by the disc  166 . 
     From the drawings and the above description, it is apparent that a vapor recovery fuel dispensing nozzle constructed in accordance with the invention provides desirable features and advantages. As one advantage, the vapor flow responsive control valve  160  remains normally closed until it senses a return vapor flow sufficient to open the valve from its closed position to its fully open position. This occurs on a vacuum-assist nozzle or when there is an overflow of vapors from the retention vapor canister on an ORVR type vehicle. Once the magnetic attraction between the magnet  176  and the disc  166  is overcome by the vapor flow, the disc  166  shifts upwardly to its fully open position since the magnetic attraction reduces as the disc moves upwardly. In addition, the magnetically actuated vapor flow control valve eliminates any springs which commonly degrade due to cyclic operation and also eliminates resilient or flexible diaphragms which degrade due to gasoline vapor environment. In addition, the permanent magnet forces are more consistent than springs and do not change due to cyclic operation. The metal disc  166  is also impervious to gasoline vapors. 
     While the form of nozzle and vapor flow responsive valve herein described constitute a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of the invention, and that changes made therein without departing from the scope and spirit of the invention as defined in the appended claims.