Abstract:
Drive off is prevented by having a grasp assembly engage the restrictor plate of the fill pipe of a motor vehicle when the nozzle spout is inserted. After the fuel pump is started and pressure is placed on the fuel, fuel is admitted into the nozzle by pressing on the hand lever to open the poppet valve. Fuel pressure in the nozzle activates a lock actuator system, to prevent removal of the spout from the fill pipe, by a lock system that prevents a grasp assembly latch from retracting from the fill pipe restrictor plate.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   A fuel dispensing nozzle at a filling station is provided with a mechanism that engages with the fill pipe activated by the initial insertion of the spout. The mechanism is locked in position by fuel pressure that can only be inactivated remotely by removal of fuel pressure or paid at the pump override, thereby preventing drive off without payment. 
   2. Description of Related Art 
   The concept of providing fuel nozzles with spout extensions to secure the nozzle to a fuel tank to prevent spilling and need to hold the nozzle are old. M. McCune, U.S. Pat. No. 1,457,535, issued Jun. 5, 1923, and L. Dorris, U.S. Pat. No. 1,515,844, issued Nov. 18, 1924, and, J. Seidel, U.S. Pat. No. 1,726,044, issued Aug. 27, 1929, and R. Chadil et al, U.S. Pat. No. 2,547,690, issued Apr. 3, 1951, and G. Moore et al, U.S. Pat. No. 3,502,121, issued Mar. 24, 1970, and C. Sunderhaus, U.S. Pat. No. 4,557,302, issued Dec. 10, 1985, are examples. The use of pull away parts to preclude unnecessary damage when a vehicle operator pulls off with the nozzle still in the fill pipe is known with M. Carder et al, U.S. Pat. No. 6,123,123, issued Sep. 26, 2000, examples 
   SUMMARY OF THE INVENTION 
   With the advent of self service filling stations around the world, a huge expense to operators of such filling stations deals with intentional and non-intentional thievery of the petroleum product. At times, fuel is unintentionally stolen from filling stations due to the mistaken belief that a spouse paid for the fuel or the customer forgets to pay after spending an extended period of time in the filling station. However, most of the time the act of thievery is intentional. Unfortunately, the crime is not often pursued by the local authorities due to the low value of the crime of less than $30. If a fill station combats the thievery by a requirement of pre-paying for fuel, they lose many customers due to the added inconvenience. Gasoline drive-offs are a $272 million per year problem to the 153,200 gasoline dispensing convenient stores in the USA, as well as additional losses to all other non-prepay fuel dispensing stations throughout the world. 
   A fuel dispensing nozzle contains a handle driven poppet valve that allows the customer to manually regulate the approximate 10 psi of gasoline pressure delivered by the pump. The nozzle contains a disposable 13/16″ diameter aluminum spout which is inserted past the gasoline tank filler inlet restrictor within the fill pipe on all unleaded vehicles since 1974. A trigger mechanism interacts with the customer&#39;s fill pipe to actuate an interlocking lever having a catch that will interlock with the inlet restrictor. The interlocking lever catch is locked in place by the 10 psi of gasoline fluid pressure. By requiring the cashier to turn off the pump, fluid pressure is removed from the nozzle to pivot the interlocking lever and permit the dispensing nozzle to be safely removed from the customer&#39;s vehicle at the cashier&#39;s convenience. 
   The interlocking lever catch is activated by pivoting a latch under the restrictor plate by engaging a trigger with the restrictor plate against spring pressure. The latch is locked in place by fuel pressure acting against a diaphragm that pulls a lock pin into a lock recess against spring pressure to prevent the latch from pivoting out of contact with the restrictor plate. When fuel pressure is released, by cutting off the pump, the diaphragm returns to a pre-full position that pushes the lock pin out of the lock recess by return lock pin spring pressure. The latch pivots from under the restrictor plate under trigger spring return pressure or force. 
   If the customer fails to pay the cashier and drives off while the fuel nozzle is still connected to the fill pipe, an OSHA mandated breakaway will disconnect the nozzle from the hose. The breakaway disconnects whenever a force of 350 lb. is applied and allows only a fraction of an ounce of fuel to spill. The cost of the break-away gasoline nozzle with modified spout, and re-installation of a new spout, will be more than the minimum felony threshold of $300. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side sectional view of the fuel nozzle showing the assemblies of the invention. 
       FIG. 2  is a partial side sectional view of the grasp and lock assembly shown in  FIG. 1 . 
       FIG. 3  is a partial side sectional view of the lock actuator assembly shown in  FIG. 1 . 
       FIG. 4  is a partial side sectional view of the lock assembly shown in  FIGS. 1 and 2 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The invention combines or modifies the standard fuel nozzle  101  with a drive off prevention system by adding a fuel fill pipe restrictor grasp assembly  110 , lock actuator assembly  120 , and a locking assembly  130 . 
   The standard fuel nozzle components include a nozzle housing  103 , hand lever  104 , valve stem  105 , poppet valve  106 , poppet valve spring  123  and venture  125  that conduct fuel to the vehicle fuel tank through the fill pipe restrictor plate  108  from a reservoir or storage tank. 
   The hand lever  104  provides the customer with the means to initiate the flow of fuel through the nozzle by exerting upward force on the valve stem  105  and on the poppet valve  106 . The main poppet valve spring  123  must be compressed in order to allow fuel, present in the entry tube of the main body, to proceed through the main body and out to the spout  102 . When a customer pulls up on the hand lever  104 , the compression of this spring will permit the poppet valve to lift allowing fuel to proceed into the main body passage. Venturi  125  is the standard means of detecting that the vehicle fill pipe is full of fuel. The venturi produces a slight vacuum when fuel is flowing and sucks in air from the vent tube which has been routed to the distal end of the spout. The venturi can also produce a vacuum in the venturi housing  124 . 
   The elements of the grasp assembly  110 , featured in  FIG. 2 , include the spout  102 , the trigger  111 , the slide arm  112 , grasp spring  113 , and the latch  115 . 
   In this particular embodiment, the spout  102  is preferably constructed of a 13/16″ OD diameter aluminum tube that is bent into a proper shape by a die-pressing operation. A slot  109  is cut into the straight end (the distal end) of the spout into which the latch  115  is inserted, and a widened body within the curved section of the spout provides for the locking pin housing assembly  130 . This widened body of the spout is intended to maintain the flow rate through the spout, despite the small obstruction presented by the latch  115  and the locking pin housing assembly  130 . The trigger  111  is attached to or is a part of the slide lever arm  112 . The trigger  111  works with the slide lever arm  112  to cause the latch  115  to pivot about its fulcrum  116  that will engage the latch with the restrictor plate  108 . The trigger  111  is spring loaded and will slide from the distal end of the spout  102  whenever the spout is inserted into a fill-pipe. When the trigger  111  is pushed back from its normal fully extended position, by action of the nozzle operator inserting the spout into the fill pipe, by contact with the fill pipe or restrictor plate  108 , the slide lever arm  112  is pushed inwardly. The spout outer spring  113  wraps around the outside of the spout  102  at the straight distal end and interacts with the trigger  111 . The latch  115  has its fulcrum  116  as close as possible to the inner curve of the spout  102 . The latch hook  119  catches onto the distal or inner side of the restrictor plate. The latch is locked in position by action of the locking pin assembly  130  when fuel pressure causes the locking pin wire  126  to pull the locking pin  139  into the lock recess  132 . 
   The elements of the lock actuator assembly  120 , featured in  FIG. 3 , include the diaphragm  121 , diaphragm clamp  122 , and cable or wire  126 . 
   The actuator diaphragm  121  can be an accordion or elastic type, a rubber gasket that is sensitive to fuel pressure and deforms to transmit the fuel fluid pressure to the locking pin  139  through the actuator wire  126  is preferred. The actuator diaphragm clamp  122  can be a set of dual hardened plastic disks, forming a sandwich with the top portion of the actuator diaphragm  121  lying between the disks, and secured to the diaphragm by a screw or other clamping means. The screw is in turn connected to the one end of actuator wire  126 . The locking pin wire, with or without a cable housing, is a small gauge wire that provides the means needed to transmit the movement of the actuator diaphragm  121  to the locking pin  139  connected to the other end of the wire. The wire provides the means by which the tension, or absence of tension, in the actuator diaphragm  121  is communicated to the locking pin assembly  130 . The second end of the locking pin wire is attached to the locking pin  139  by a wire lock  133 . The locking pin wire is threaded through the nozzle between the actuator diaphragm clamp  122  and lock pin  139 . 
   The elements of the locking assembly  130 , featured in  FIG. 4 , include the lock housing  131 , the locking pin  139 , the lock cap  137 , the lock spring  138 , and the latch spring  117 . 
   The lock  130  locking pin housing  131  establishes communication between the lock actuator assembly  120  and the grasp assembly  110 . The locking pin wire  126  extends between the actuator diaphragm  121  and the locking pin  139 . The latch  115  in the locked position is alined with the locking pin housing by means of the locking pin  139  extending into the lock recess  132  in the locking pin housing  131 . The locking pin, when extended into the locking pin housing, prevents the latch  115  from pivoting back to the unlocked position even when the trigger  111  with the slide lever arm  112  has been moved back to its at rest position or forward past the latch fulcrum  116 . The locking pin cap  137  fits into a cavity or latch recess  136  in the inner end of the latch  115  adjacent the locking pin  139 . It houses and is acted on by the latch spring  117  that serves to pivot the latch  115  from the locked position when the locking pin  139  and the trigger  111  are in the unlocked position. This can only happen after the locking pin  139  has been retracted from the lock recess  132  in the locking pin housing  131 . The locking pin spring  138  is normally extended toward the distal end of the spout  102 . 
   Fuel pressure moves the lock pin  139  into the lock recess  132  by pulling on the actuator wire compressing the locking pin spring  138 . The release of fuel pressure relieves pressure on the actuator cable and enables the locking pin spring  138  to force the lock pin out of the lock recess allowing the latch to be rotated by the latch spring  117  to unlock the locking mechanism. 
   The locking pin cap spring  117  acts to push down on the inner end of the latch  115  with sufficient force to retract the hook  119  of the latch from the restrictor plate  108  releasing the fuel nozzle from the vehicle. This can only occur when the fuel pressure is shut off deflating the actuator diaphragm  121  allowing the locking pin  139  to retract from the lock recess  132  in the locking pin housing  131 . In this position, the locking pin cap spring  117  will extend downward to pivot the latch clockwise and the latch hook  119  away from the restrictor plate. 
   In operation, to prevent drive off at the gas pump, a trigger  111 , under the grasp spring  117  pressure, is moved inward on contact with the fill tube of a gas tank. The trigger  111  is attached to slide arm  112  on its distal outer end and has an inwardly extending knob  114  on its inner end. The knob reciprocates under a grasp fulcrum  116  at an intermediate section of a latch  115 . The latch has an extension or hook  119  on its outer end, that can fit under the outer lip  108  of a fill tube flange, and has a locking assembly  130  at its inner end. The latch  115  pivots around the intermediate pin fulcrum  116 . As the trigger  111  is moved in, the knob  114  on the slide arm  112  is guided by the spout  102  and moves against grasp spring  113  pressure and against latch spring  117  pressure, as soon as the knob  114  pass the grasp fulcrum  116 . The knob  114  moves against the inner end of the arm and rotates it counterclockwise around the grasp fulcrum  116  as it moves inwardly past the grasp pivot point. This counterclockwise rotation of the latch moves the hook  119  on the outer end of the latch outwardly and under the flange  108  of a fill tube to engage the nozzle with the fill tube. 
   To lock the latch  115  in the engaged position, an elastic, accordion, or other resilient diaphragm  121  is moved out under fuel pressure, created by the fuel pumping system, when the pump is energized by an attendant or customer, and the hand lever  104  is pressed in. A wire or stiff cable  126 , that can have a covering, has one inner end attached to the diaphragm, extends to a locking pin  139  attached to its outer end. The locking pin is moved inward, due to fuel pressure causing the wire to pull on the locking pin, against locking spring  138  pressure. The fuel pressure moves the locking pin  139  into a lock recess  132  in locking pin housing  131 . The lock housing  131  is stationary with the nozzle and has the opening  132  that can receive the locking pin  139  when the trigger  111  is moved inward. The slide  112  knob  114  after moving past the grasp fulcrum  116  pivots the latch  115  counterclockwise and alines the pivot pin  139  with the lock recess  132  in the lock housing  131 . The lock recess  132  has a guide hole or central passage  134  at its base through which the activator cable or wire  126  extends into the locking pin. This guide-hole will receive the wire routed through the body of the fuel nozzle. The activator wire through the lock pin passage  134  guides the locking pin  139  into the lock recess  132 . The fuel pressure causes the wire  126  to pull the lock pin  139  into the recess  132  to prevent the latch  115  from being removed from the fill tank pipe. In this position the nozzle cannot be removed from the fill tube. 
   To remove the nozzle requires the release of the lock pin by removal of fuel pressure, not directly under consumer control. The fuel pump can be shut off only by the station attendant or paying at the pump control. When the fuel pressure is removed, with or without a vacuum assist, the locking pin  139  moves out under lock spring  138  pressure, separating the locking pin  139  from the locking pin housing  131 . Removal of the locking pin from the housing permits the latch spring  117  to pivot the latch  115  clockwise around pivot  116  and the latch hook  119  away from the fill tube lip and removal of the nozzle from the fill tube as grasp spring  113  moves the trigger  111  outward. 
   The locking system  130  could be defeated by purposely wrapping tape around the spout in order to prevent the latch from pivoting out and catching the restrictor plate. A vent valve  118  has been added that will prevent fuel from being pumped while the latch is in the fully retracted position. 
   It is believed that the construction, operation and advantages of this invention will be apparent to those skilled in the art. It is to be understood that the present disclosure is illustrative only and that changes, variations, substitutions, modifications and equivalents will be readily apparent to one skilled in the art and that such may be made without departing