Abstract:
A multiproduct fuel dispenser for dispensing a plurality of fuels stored in a plurality of reservoir tanks comprising a nozzle for dispensing fuel, fuel delivery lines for delivering fuel from the plurality of reservoir tanks to the nozzle, and a common fuel meter operatively connected to the fuel delivery lines for quantifying the amount of fuel dispensed from the plurality of reservoir tanks, the common fuel meter having an internal volume no greater than 0.1 gallons.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to a multiproduct fuel dispenser and, more particularly, to such a dispenser that feeds more than one product through a common meter.  
         BACKGROUND OF THE INVENTION  
         [0002]    Many gasoline service stations require the installation of multiproduct fuel dispensers or pumps, each for dispensing a plurality of different grades, or octane levels, of gasoline products at each fueling station. Conventionally, three different products are provided per fueling station, namely a high octane fuel, a medium octane fuel and a low octane fuel. Mixing of these various products can result in the dilution or lowering of the octane level of the high and medium octane fuels which can adversely affect the performance of the customer&#39;s automobile. Testing procedures have therefore been developed in the United States to certify the octane levels of the fuels dispensed from commercial fuel dispensers. The testing and certification procedures are set forth in the National Conference on Weights and Measures Publication No. 12, entitled “Examination Procedure Outlines for Weighing and Measuring Devices.” Pursuant to these testing guidelines, the person conducting the test is required to flush at least 0.3 gallons of fuel from the dispenser before taking the test sample. See page 57, fn. 1. Thus, in dispensers used at United States gasoline service stations, a slight mixing of the various fuel products of a multiproduct fuel dispenser may occur, so long as the contaminated product is flushed from the system during the first 0.3 gallons of discharge.  
           [0003]    To minimize the mixing of the various products dispensed from a multiproduct fuel dispenser, known dispensers typically include a separate flow path for each product from its reservoir product tank which stores the fuel to the outlet nozzle which introduces the fuel into the consumer&#39;s automobile. These systems therefore require the duplication of the components disposed between the tank and the nozzle for each fuel product, including the flow meter. In this manner, however, no contamination of the octane level of the products can occur. Such dispensers are known as “wet hose systems” as the hose, as well as the flow meter and other delivery components, remain filled with fuel from the most recent use. Through the use of such separate hoses, meters, etc., dispensers of the prior art avoid contamination of fuel being dispensed at a particular time with fuel from a previous use that would otherwise remain in the system at the termination of the last dispensing cycle. Spalding, U.S. Pat. No. 5,332,011, a patent assigned to the assignee of the present invention, discloses such a dispenser, in which three nozzles, fuel hoses and flow meters, each for a different grade of gasoline, are combined in a single dispenser.  
           [0004]    There are many disadvantages in the use of discrete delivery systems for each product fed through a multiproduct fuel dispenser. For example, the cost of such dispensers is increased due to the requirement for multiple hoses, nozzles and meters. Also, the overall size and space requirements of such a dispenser are increased due to the requirement to house the multiplicative components. In addition, and especially with respect to the flow meters, the cost of maintenance and repairs is increased for each discrete delivery system included in such dispensers.  
           [0005]    In an effort to overcome some of the above problems, multiproduct fuel dispensers have been developed that comprise tri-axial fuel hoses having three concentric passages within a single hose that lead to a single nozzle. Such devices simplify operation for the consumer as there is only a single nozzle, but they do not alleviate the need for separate flow meters for each product or improve the maintenance and repair costs. Moreover, such devices might actually increase the cost of the dispenser due to the complexity of the tri-axial hoses.  
           [0006]    Other multiproduct fuel dispensers have been developed in which the supply lines from each reservoir tank are manifolded into a single fuel hose downstream of the flow meter, which hose then leads to a single nozzle. Although this eliminates the multiplicity of nozzles and hoses, the problems associated with the multiplicity of flow meters, such as complexity, space limitations, and repair and maintenance expenses, remain.  
           [0007]    What is needed is a multiproduct fuel dispenser that uses a common flow meter for dispensing a multiplicity of fuels.  
         SUMMARY OF THE INVENTION  
         [0008]    It is therefore an object of the present invention to provide a multiproduct fuel dispenser that uses a common meter for dispensing a multiplicity of fuels.  
           [0009]    It is a further object of the present invention to provide a dispenser of the above type in which less than 0.3 gallons of fuel remains in the common fluid path of the dispenser following its use.  
           [0010]    It is a still further object of the present invention to provide a dispenser of the above type in which either a single nozzle or multiple nozzles can be employed.  
           [0011]    It is a still further object of the present invention to provide a dispenser of the above type in which the complexity, space limitations, original cost and repair and maintenance expenses are all reduced relative to current dispensers.  
           [0012]    Towards the fulfillment of these and other objects, according to the multiproduct fuel dispenser of the present invention, a dispenser is provided having a single common fuel meter per fueling station for receiving a plurality of grades of fuel from fuel reservoir tanks. The internal volume of the fuel meter is such that no more than 0.1 gallons of fuel remain in the fuel meter after use of the dispenser. After passing through the fuel meter, the fuel can flow either through a common hose and nozzle to the customer&#39;s fuel tank, or alternatively, through separate hose and nozzle paths for each grade of fuel dispensed from the dispenser. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    The above brief description, as well as further objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of the presently preferred but nonetheless illustrative embodiments in accordance with the present invention when taken in conjunction with the accompanying drawings wherein:  
         [0014]    [0014]FIG. 1 is a schematic view of a prior art dispenser; and  
         [0015]    [0015]FIG. 2 is a schematic view of the dispenser of the present invention. 
     
    
     DESCRIPTION OF THE PRIOR ART  
       [0016]    Referring to FIG. 1 of the drawings, a prior art multiproduct fuel dispenser is shown schematically and generally referred to with reference numeral  10 . The dispenser  10  receives fuel from a plurality of underground fuel reservoir tanks  12   a - 12   c,  each of which stores a different grade of fuel such as high, medium and low octane. Fuel from the reservoir tanks  12   a - 12   c  flows into the dispenser  10  via separate fuel delivery lines  14   a - 14   c,  each under the control of a flow control valve  16   a - 16   c,  respectively. Flow meters  18   a - 18   c  are disposed in each of the fuel delivery lines between each reservoir tank  12   a - 12   c  and its associated flow control valve  16   a - 16   c,  respectively. Each flow meter  18   a - 18   c  generates an output signal in proportion to the gasoline flow through such meter to allow the customer to control the total amount of fuel dispensed. The flow meters  18   a - 18   c  are conventional in design, and each could, for example, be a positive displacement meter comprising a fluid oscillator, a piezoceramic transducer and an electrical connector.  
         [0017]    The fuel delivery lines  14   a - 14   c  converge downstream of the flow control valves  16   a - 16   c  at a convergence point “A” into a single fuel delivery line  20  which passes the fuel out of the dispenser  10  via an outlet casting  22 . A flexible hose  24  extends from the outlet casting  22  and terminates in a nozzle  26  designed for insertion into a customer&#39;s automobile fuel tank (not shown). A product selection panel  28  having a plurality of buttons  28   a - 28   c  corresponding to the grades of fuel available through the dispenser  10  is mounted to the dispenser  10  and, together with the nozzle  26 , controls the operation of the flow control valves  16   a - 16   c  in a conventional manner to allow the customer to select the desired grade of fuel from the reservoir tanks  12   a - 12   c.    
         [0018]    It should be understood that multiproduct fuel dispensers such as the dispenser  10  typically contain two fueling stations on opposing sides to service two customers at a time, each having a fuel delivery system as just described for dispensing fuel from the reservoir tanks  12   a - 12   c.  As such dispensing stations are identical, only one fueling station has been described.  
         [0019]    In operation of the prior art dispenser  10 , the customer places the nozzle  26  into the automobile fuel tank (not shown) and selects a desired grade of fuel, i.e. the fuel from reservoir tank  12   a,  from the product selection panel  28  by pressing the appropriate button  28   a - 28   c,  i.e. button  28   a.  This selection is electronically transferred from the product selection panel  28  to the appropriate flow control valve  16   a - 16   c  in a conventional manner, in this case flow control valve  16   a.  Then, when the customer activates the nozzle  26 , the flow control valve  16   a  opens, thereby allowing fuel in the reservoir tank  12   a  to travel through the fuel delivery line  14   a,  through meter  18   a,  into the fuel delivery line  20  and the hose  24  and ultimately into the customer&#39;s fuel tank via the nozzle  26 . The meter  18   a  tracks the amount of fuel flowing through the line, and thus the amount flowing into the customer&#39;s fuel tank, to enable the dispenser  10  to calculate the cost of the dispensed fuel. When the customer&#39;s fuel tank is full, or at anytime that the customer desires to stop the fuel delivery by deactivating the nozzle  26 , the flow control valve  16   a  closes to stop the flow of fuel from the reservoir tank  12   a.    
         [0020]    Upon the stoppage of fuel delivery, the fuel delivery line  14   a,  the meter  18   a,  the flow control valve  16   a,  the fuel delivery line  20 , the hose  24  and the nozzle  26  all remain full of fuel from the reservoir tank  12   a.  This causes no problem if the next customer also selects the fuel from the reservoir tank  12   a,  but if the fuel from either reservoir tank  12   b  or  12   c  is selected, then the reservoir tank  12   a  fuel remaining in the fuel delivery line  20 , the hose  24  and the nozzle  26  will be commingled with the newly selected fuel, thereby causing a change in the dispensed fuel characteristics and octane level. As discussed above, testing procedures have been developed in the United States to certify the octane levels of the fuels dispensed from commercial fuel dispensers to force the manufacturers of multiproduct fuel dispensers to minimize such commingling. These testing and certification procedures allow only a slight mixing of the various fuel products of a multiproduct fuel dispenser to occur. More specifically, the contaminated product must comprise no more than 0.3 gallons of fuel.  
         [0021]    In conventional multiproduct fuel dispensers such as the dispenser  10 , the amount of fuel remaining in the hose  24 , measured between and including the outlet casting  22  and the nozzle  26 , is around 0.2 gallons. Conventional flow meters, such as the flow meters  18   a - 18   c,  contain in excess of 0.1 gallons of fuel after use, and thus conventional multiproduct fuel dispensers have required a separate flow meter for each fuel reservoir tank to meet the United States testing and certification procedures.  
       DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0022]    Referring now to FIG. 2, a multiproduct fuel dispenser of the present invention is shown schematically and generally referred to with reference numeral  30 . The dispenser  30 , like the prior art dispenser  10 , receives fuel from a plurality of underground fuel reservoir tanks  32   a - 32   c,  each of which stores a different grade of fuel such as high, medium and low octane. Also like the prior art dispenser  10 , separate fuel delivery lines  34   a - 34   c  pass the fuel from the reservoir tanks  32   a - 32   c  into the dispenser  30  under the control of flow control valves  36   a - 36   c;  however, in the dispenser  30  of the present invention, the fuel delivery lines  34   a - 34   c  converge into a single fuel delivery line  38  at a convergence point “A” upstream of a single flow meter  40 . The flow meter  40  is disposed in the fuel delivery line  38 , which line passes the fuel out of the dispenser  30  via an outlet casting  42 . A flexible hose  44  extends from the outlet casting  42  and terminates in a nozzle  46  designed for insertion into a customer&#39;s automobile fuel tank (not shown). A product selection panel  48  having a plurality of buttons  48   a - 48   c  corresponding to the grades of fuel available through the dispenser  30  is mounted to the dispenser  30  and, together with the nozzle  46 , controls the operation of the flow control valves  36   a - 36   c  in a conventional manner to allow the customer to select the desired grade of fuel from the reservoir tanks  32   a - 32   c.    
         [0023]    Like the flow meters  18   a - 18   c  of the prior art, the flow meter  40  generates an output signal in proportion to the gasoline flow through the meter to allow the customer to control the total amount of fuel dispensed; however, as opposed to flow meters of known multiproduct fuel dispensers, the fuel meter  40  of the present invention has a smaller internal volume such that no more than 0.1 gallons of fuel remains in the fuel meter  40  after use of the dispenser  30  as is further described below.  
         [0024]    It should be. understood that the dispenser  30  contains two fueling stations on opposing sides to service two customers at a time, each having a fuel delivery system as just described for dispensing fuel from the reservoir tanks  32   a - 32   c.  As such fueling stations are identical, only one station has been described. In addition, it should be emphasized that since FIG. 2 is merely a schematic representation of the basic components of the assembly of the present invention, the exact location, size and lengths of the components can vary within the scope of the invention. For example, the fuel meter  40  can be disposed in closer proximity to the outlet casting  42  to reduce the length of the fuel delivery line  38  in order to further reduce the amount of fuel remaining in the dispenser after use.  
         [0025]    The operation of the dispenser  30  of the present invention is similar to the operation of the prior art dispenser  10  in that the customer selects a desired grade of fuel from the product selection panel  48  by pressing the appropriate button  48   a - 48   c.  This selection is electronically transferred from the product selection panel  48  to the appropriate flow control valve  36   a - 36   c  in a conventional manner. Then, when the customer activates the nozzle  46 , the appropriate flow control valve  36   a - 36   c  opens, thereby allowing fuel from the selected reservoir tank  32   a - 32   c  to travel through its associated fuel delivery line  34   a - 34   c,  through the convergence point “A” into the fuel delivery line  38 , and into the fuel meter  40 . The fuel meter  40  tracks the amount of fuel flowing through the line, and thus the amount flowing into the customer&#39;s fuel tank via the hose  44  and the nozzle  46 , to enable the dispenser  40  to calculate the cost of the dispensed fuel. When the customer&#39;s fuel tank is full, or at anytime that the customer desires to stop the fuel delivery by deactivating the nozzle  46 , the activated flow control valve  36   a - 36   c  closes to stop the flow of fuel from the selected reservoir tank  32   a - 32   c.    
         [0026]    Upon the stoppage of fuel delivery, the selected fuel delivery line  34   a - 34   c  and flow control valve  36   a - 36   c,  the fuel meter  40 , the fuel delivery line  38 , the hose  44  and the nozzle  46  all remain full of fuel. Unlike the dispenser  10 , however, the fuel remaining in the dispenser  30  is equal to or less than 0.3 gallons of fuel due to the reduced internal volume of the single fuel meter  40 . In this manner, even if the next customer selects a different grade of fuel, only a slight commingling of fuels will occur. Thus, the dispenser  30  can pass the United States National Conference on Weights and Measures testing and certification procedures for octane certification as the remaining fuel (≦0.3 gallons) will be flushed from the dispenser  30  before the test sample is collected.  
         [0027]    The multiproduct fuel dispenser  30  of the present invention thus provides several benefits and technical advantages over prior art dispensers. Foremost, by employing a single common fuel meter  40 , both the original costs, and the expected repair and maintenance costs, of the dispenser  30  are reduced due to the elimination of relatively expensive and high maintenance component parts, such as multiple fuel meters. Moreover, as parts have been eliminated, the overall size and space requirements of the dispenser  30  are reduced. Importantly, these benefits and advantages are achieved with a multiproduct fuel dispenser that still passes the United States octane certification procedures as no more than 0.3 gallons of fuel remain in the dispenser  30  that can be commingled with fuels of different octane levels.  
         [0028]    It should be understood that additional variations may be made to the preferred embodiment of the invention discussed above without departing from the spirit and scope of the present invention. For example, although the dispenser  30  has been described as having a single hose  44  and a single nozzle  46 , the fuel delivery line  38  could be replaced with a plurality of fuel delivery lines, one for each product to be dispensed from the dispenser, for receiving fuel from the common fuel meter  40 . Each such fuel delivery line would be attached to a separate hose and nozzle. In such a system, additional flow control valves would be required downstream of the flow meter  40 , in addition to the flow control valves  36   a - 36   c,  to control the flow of fuel through the dispenser.  
         [0029]    Further modifications, changes and substitutions are intended in the foregoing disclosure and in some instances some features of the invention will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the invention.