Abstract:
A method for preventing use of an unapproved fuel in a diesel engine uses a fuel tank that does not have a conventional fueling opening and has a puncturable fitting for connection to fuel lines of the engine. The engine fuel lines terminate in a mount that has fangs adapted for puncturing the fuel tank fitting. The tank is against the mount so that the fangs puncture the fitting to allow fuel to flow from the tank to the fuel line. Since the tank does not have a fuel filling opening, it cannot be refilled without special equipment and must be removed from the engine for refilling.

Description:
SPECIFIC DATA RELATED TO THE INVENTION  
       [0001]     This application claims the benefit of U.S. Provisional Application No. 60/510,859 filed Oct. 14, 2003. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to diesel engines, and, more particularly, to a method and apparatus for assuring that a diesel engine is used only with a fuel designed specifically for operation in the engine.  
         [0003]     Diesel engines are well known in the art and multi-cylinder diesel engines have long been used in powering large machinery such as locomotives and over-the-road trucks. Smaller multi-cylinder diesel engines have also been adapted for use in certain automobiles. Currently, even smaller single cylinder diesel engines have been developed for use in relatively low power applications. All of these diesel engines routinely produce high levels of hydrocarbon emissions and are therefore not particularly environmentally friendly. Applicant has found that the hydrocarbon and other emissions from such diesel engines can be significantly reduced by utilization of a bio-diesel fuel in the engines. In particular, applicant has found that the use of a fuel manufactured from used vegetable oil can be used in these engines and will cause the engines to fall well within the emissions guideline of the United States Environmental Protection Agency. The problem that the EPA has with such engines is that the fuel source must be controlled in such a manner as to prevent conventional hydrocarbon-base diesel fuel from being used in such engine. If a user of such engine substitutes ordinary hydrocarbon-base diesel fuel into the engines, the emissions from the engine will likely exceed the EPA requirements and thus result in an engine which produces environmentally harmful pollutants.  
         [0004]     An example of a single cylinder diesel engine is a Model 186F available from ETQ Power Products of Baldwin Park, Calif. The Model 186F diesel engine is rated at 10 horsepower but has been known to produce significant hydrocarbon emissions when operating on conventional hydrocarbon-base diesel fuel. This same engine has been tested with bio-diesel fuel manufactured from used vegetable oil and found to produce emissions that are well below conventional EPA guidelines when using this alternative fuel. Accordingly, EPA may approve use of this engine in the U.S. if the engine can be limited to operation on bio-diesel fuel.  
         [0005]     Applicant has found that one method of preventing substitution of hydrocarbon based diesel fuel into a diesel engine is to provide a fuel tank for use on such engines that is not refillable by the user of the engine. For example, the fuel tank is not provided with a refill cap of the conventional type. In applicant&#39;s invention, the fuel tank is removable from the engine and must be returned to a dealer in such fuel tanks for replacement. Only the dealer has the equipment necessary to refill the tank and to restore it to its normal operating condition. For this purpose, the fuel tank must be readily removable from the diesel engine and easily attachable to the engine in order to allow the consumer to replace the tank as necessary. Further, the attachments to the engine should be designed in such a manner that they cannot be bypassed so as to allow a user to connect a different type of tank to the engine. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]      FIG. 1  is a simplified schematic representation of a fuel tower used in one embodiment of the present invention;  
         [0007]      FIG. 2  illustrates the fuel tower of  FIG. 2  with a fuel tank positioned for coupling to the tower;  
         [0008]      FIG. 3  illustrates the fuel tower of  FIG. 1  with fuel lines coupled to the fuel tank of  FIG. 2 ;  
         [0009]      FIG. 4  illustrates coupling of the fuel lines to the fuel tank;  
         [0010]      FIG. 5  illustrates the fuel line receptacles of the fuel tank;  
         [0011]      FIG. 6  illustrates another embodiment of the invention using a fuel tank formed from a cola container;  
         [0012]      FIG. 7  is a simplified illustration of a fuel cap used with the tank of  FIG. 6 ;  
         [0013]      FIG. 8  illustrates the tank of  FIG. 6  with the cap of  FIG. 7  partially installed;  
         [0014]      FIG. 9  is a top view of the cap of  FIG. 7 ;  
         [0015]      FIG. 10  illustrates one form of attachment of the tank of  FIG. 8  to a fuel plug or fitting;  
         [0016]      FIG. 11  illustrates the system of  FIG. 10  in a locked position;  
         [0017]      FIG. 12  shows one form of fuel plug used in  FIG. 10 ;  
         [0018]      FIG. 13  shows the connecting sleeve of  FIG. 10 ;  
         [0019]      FIG. 14  is a side view of the lever of  FIG. 6 ;  
         [0020]      FIG. 15  is a cross-sectional view of the fuel tank cap; and  
         [0021]      FIG. 16  is a view of the connecting end of the fuel tank. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]      FIGS. 1-5  illustrate one embodiment of a removable fuel tank which minimizes the opportunity for a user of a diesel engine to connect the fuel lines to the diesel engine for receiving fuel from a source other than the designed fuel tank. As shown in  FIG. 1 , a diesel engine typically has a pair of fuel lines,  10  and  12 , with the line  10  representing the fuel feed line from a fuel tank to the engine while line  12  represents a fuel return line from the engine to the fuel tank. Both the fuel return line and the fuel feed line are mounted within a support block  14 . The support block  14  rests within a recess in a fuel tank support  16  that is adjacent the diesel engine (not shown). The tank support  16  is spring mounted in the vertical direction in  FIG. 1 . The support  16  can be pressed downward to expose the support block  14 . As shown in  FIG. 2 , the fuel tank  18  has a lower recess  19  that fits over the support block  14  while the other lower edges  20  of the tank press downward on the support  16 . For purposes of description, it may be noted that the block  14  is also referred to as the fuel tower.  
         [0023]     Once the tank  18  has been placed on the platform or support  16  and pressed downward exposing the fuel tower or block  14 , the tank is then slid in the direction of the arrow  22  as shown in  FIG. 3 . This lateral movement causes the block  14  to move and exposes a pair of fuel fittings  24  on the end of the fuel feed line  10  and fuel return line  12 . The fittings  24  are positioned to fit into a pair of mating receptacles in the fuel tank  26  so that the final assembly appears as shown in  FIG. 4 .  
         [0024]     A cross-sectional view taken along the lines  6 - 6  of  FIG. 3  shows the mating receptacles  28  adapted for receiving the fuel fittings  24 . In a preferred form, the mating receptacles  28  are conventional elastomeric diaphragms that are punctured by the fuel fitting  24  and seal around the fittings when they enter the fuel tank  18 . Since these receptacles  28  are punctured by the fittings  24 , the tank will leak if fuel is placed in the tank after puncturing of the fittings thus deterring re-use of the tank.  
         [0025]     As shown in  FIG. 3 , the fuel tank  18  may be latched in place by a pivoting latch member  30  at one edge of the support  16 . The tank  18  is urged against the latch  30  by spring action from the block  14 . The spring function for block  14  is not shown but its implementation will be apparent to persons skilled in the art just as the spring action for support  16  will be apparent. The block  14  has a cutaway portion at  32  which allows it to move laterally over top edge  34  of support  16 . When the tank  18  is to be removed, the latch  30  is released and allows the tank to be slid toward the latch so that the fittings  24  disconnect and the tank lifted from support  16 . If needed, a latch or other clamp mechanism may be used to hold the side of the tank opposite latch  30  to the support  16 . The tank  18  can be refilled by removing the receptacles  28 , filling the tank with fuel and then installing new, unpunctured receptacles  28 .  
         [0026]     An alternate embodiment of the inventive removable fuel tank is shown in  FIG. 6 . In this figure, the tank utilizes a conventional two or three liter bottle of the type typically used for containing soft drinks, since such bottles are inexpensive, plentiful and can be discarded after a single use. In  FIG. 6 , an implementation using such a disposable bottle  40  is shown coupled to a set of handles  42  on a typical lawn mower incorporating a small diesel engine (not shown). The fuel containing tank or bottle  40  is supported in a horizontal position but it will be recognized that other positions could be utilized and may, in fact, be preferred as will be described later. In the illustrated arrangement, the base of the bottle  40  is supported in a structure  44  that is formed as part of a cradle  46  for supporting the removable tank and providing a fixture for attaching the fuel lines of the engine. In the illustrative embodiment, the cap  44  is attached to the support  46  through a spring loaded sliding joint at  48 . This allows the cap  44  to be displaced laterally for insertion of the tank or bottle  40  into the assembly. The spring loaded mechanism pulls the cap  44  back against the bottle to firmly seat the tank  40  and hold it in place. The sliding joint at  48  includes an internal spring which is not shown in the drawing but the construction of such joint will be apparent to those of ordinary skill in the art.  
         [0027]     The support mechanism  46  also includes a hand lever  50  which is utilized to facilitate attaching the fuel lines of the diesel engine to the tank  40 . As will be described, the mechanism for attaching the fuel lines is similar to that shown in the first embodiment of  FIGS. 1-5  and includes fittings that are specifically designed to puncture a sealing mechanism attached to the tank  40  so as to allow the fuel to be dispensed to the engine. Also visible within the tank  40  are fuel lines  52  and  54 . These lines are constructed within the tank and are preferably formed integral with the cap of the tank. The fuel line  52  shown in  FIG. 6  is actually a vent line while the fuel line  54  is the fuel feed line. Not visible in  FIG. 6  is a third line used with diesel engines as a fuel return line as was discussed with regard to  FIG. 1 .  
         [0028]     Referring now to  FIG. 7 , there is shown a cross-sectional view of one form of cap designed specifically for the present application in which the aforementioned fuel feed line A, fuel return line B and vent line C are integrally molded into the cap during manufacture thereof. The cap  60  includes a threaded portion  62  designed to thread on to the conventional threads of a typical soda or cola bottle used as a tank  40 . However, the cap further includes a flange extending annularly around the base of the cap and adapted to snap over the conventional annular rib formed around the neck of the typical cola bottle. The flange  64  is designed such that once the cap is threaded on to the bottle, the flange surface  66  (see  FIG. 15 ) will engage the rib and not allow the cap to be removed. During installation, the tapered portion  68  of the flange  64  allows the flange to ride up over the rib on the bottle. For this purpose, the lower portion of the cap may have a pair of opposed slits (not shown) to allow the lower portion of the cap to expand sufficiently to allow the flange to slip over the rib.  
         [0029]      FIG. 8  illustrates the cap  60  partially attached to the threaded opening of a bottle or tank  40  and shows the rib  69  located below the threaded portion (see also  FIG. 16 ). It will be noted that the cap  60  also includes a pair of opposed studs  70  which are used in the attachment of the tank  40  to the support mechanism  46 .  
         [0030]      FIG. 9  is a top view of the cap  60  showing positioning of the three connections into the fuel tank described above. In a preferred embodiment, the cap  60  is molded as an integral unit with the fuel feed and return lines and vent lines formed in the cap. Each of the lines must terminate at a predetermined location to enable connection of the fuel lines with the engine into the correct one of the respective lines. It is contemplated that the internal molded lines will terminate just short of penetrating the surface of the cap  60  so that there is a plastic layer of cap that closes the ends of those lines from the outer surface of the cap. In  FIG. 9 , the vent line is shown at  72 , the return line is shown at  74  and the fuel feed line is shown at  76 . It will be appreciated that the connections of the fuel lines to the cap requires that the appropriate devices that are inserted through the cap be positioned in a similar configuration in the fuel connection mechanism to be described hereinafter. While the fuel lines and vent lines connected to the cap  60  are illustrated as being relatively long in order to adapt to the use in the longitudinally oriented tank of  FIG. 6 , it will be appreciated that the lines could be of different lengths if the tank is oriented in a vertical configuration with the cap being at the lowest point. In that event, there may not be a need for any integrated fuel lines for the fuel feed and fuel return line but may simply require a longer line for the vent. It is anticipated that the vent will be required since the tank is essentially sealed and air needs to be allowed to enter the tank in order to allow the fuel to dispense from the tank. However, it is also recognized that the vent line may be avoided if the tank is positioned in a vertical orientation by adding a one-way air valve at the bottom of the tank so that when the tank is positioned in its inverted orientation, air can enter through the air intake line at the uppermost end of the tank.  
         [0031]     Turning now to  FIGS. 10 and 11 , there is shown a simplified illustration of one embodiment of the invention connecting the tank  40  to the fuel lines for the engine. Within the handle  50  described in  FIG. 6 , there is a sleeve  80  having a pair of grooves that are formed with a longitudinal slot  82  that connects to a pair of angularly arranged arcuate slots  84 . Each of the cap  60  and the holder or plug  90  of the fuel inlet lines are designed with a pair of opposed lugs  86  that fit within the slot  82  and  84 . When the fuel tank with the cap attached is pressed into proper alignment with the fuel line fittings, a pair of opposed lugs  88  slide within the slots  82 . The sleeve  80  can then be rotated and the angular portion of the slots indicated at  84  will draw the cap and fuel line plug  90  together.  FIG. 10  shows the same assembly but with the sleeve  80  rotated into the locked position.  
         [0032]     Turning to  FIG. 12 , there is shown a simplified drawing of the plug device  90  which interfaces with the cap  60  to connect the fuel and vent lines to the tank  40 . The plug  90  is securely fastened to the support apparatus  46  and is contained within the lever  50 . The plug  90  has a plurality of fangs  92 , each of which corresponds to one of the fuel or vent lines entering the rear of the plug. The short lug  88  which fits within the slot  82  in the sleeve  80  is shown on the side of the plug  90 .  
         [0033]      FIG. 13  is a simplified respective view of the sleeve  80  and illustrates the small protrusion or lug  94  which fits within a slot  96  in the lever  50 .  FIG. 14  is an inner view of the lever  50  which shows the opening  98  for receiving the sleeve  80  and also the slot  96  that receives the protrusion  94 . The protrusion and slot couple the lever and sleeve  80  together so that rotation of the lever will affect the rotation of the sleeve.  
         [0034]      FIG. 15  is a cross-sectional view of the cap  60  without the fuel and vent lines inserted. Considering  FIG. 15  in conjunction with  FIG. 16  which shows the threaded end of the tank  40 , it can be seen that the cap  60  threadedly engages the tank  40  until the flange  64  flips over the conventional annular ridge  69  near the base of the threaded portion of the tank connector  102 .