This invention relates to a fuel dispensing nozzle, such as may be utilized to dispense a variety of liquid fuels (e.g., gasoline, diesel fuel, and the like), and particularly to such a fuel dispensing nozzle which automatically shuts off the flow of liquid fuel upon the fuel tank of a vehicle becoming filled. Even more particularly, this invention relates to such a fuel dispensing nozzle which is utilized with a prepay, self-service filling station.
In recent years, there has been a marked trend toward the self-service dispensing of gasoline and other fuel products by the consumer into his vehicle. Several years ago, when self-service service stations came into existence, the service station operator merely permitted the retail customer to dispense the fuel into his vehicle without the aid of a service attendant. The customer would then walk inside the service station, report the amount of fuel purchased, and pay for the fuel. However, in many instances, service station operators found that a certain percentage of their customers would merely drive off after having dispensed the fuel, without paying.
In an effort to thwart such thefts of fuel, so-called "prepay" self-service stations were developed in which the customer first had to approach the service station attendant and prepay for the amount of fuel to be dispensed before the attendant would energize the fuel dispenser. Then, the customer would return to his car, insert the dispensing nozzle in his fuel tank, and dispense the already paid for quantity of fuel. When the predetermined, prepaid amount of fuel had been dispensed, the dispenser would automatically shut off, and the user would replace the dispensing nozzle in its appropriate holder.
However, in certain instances, it has been observed that certain conventional automatic fuel dispensing nozzles do not normally automatically shut off when the prepaid amount of fuel is dispensed and when the dispenser is automatically de-energized thus terminating the flow of fuel. If the customer does not shut off the nozzle but instead hangs it back on the dispenser in the open position, the next customer who prepays for his purchase may find that the dispensing nozzle is still in the open position such that when the dispenser is energized, fuel will be immediately dispensed therefrom, even though the dispenser nozzle is not yet inserted into the customer's tank.
Reference may be made to such U.S. Pat. Nos. as 4,397,447, 4,203,478, 4,199,012, 4,196,759, 4,139,032, 3,877,480, 3,653,415, 3,273,609, 3,196,908, and 3,805,600 for disclosures of automatic shut-off dispensing nozzles having a variety of poppet valve configurations generally in the broad field of this invention.