Abstract:
An apparatus for bleeding diesel fuel powered engines and method for using same. One embodiment of the apparatus comprises a canister for containing pressurized fuel and having a means for attaching to and engaging with a fuel system. The apparatus may be connected to the inlet side of an engine&#39;s fuel filter and, when engaged, will push the fuel into the fuel system and air out of the system without having to separately bleed each injector within the engine.

Description:
BACKGROUND OF INVENTION 
       [0001]    Diesel engines require a steady, air-free flow of fuel in order to function properly. At times, this becomes a challenge. For example, air may be released into the engine if an engine runs out of fuel; repair or replacement is required of a fuel injector nozzle, injector pump, fuel filter, or the fuel line; or for various other reasons. When this occurs, it is necessary to bleed the fuel system, replacing the air with fuel so that the engine will function. 
         [0002]    Some modern engines have self-bleeding fuel systems, but even these systems still require manual bleeding at times. Even the quickest self-bleeding systems still take some time, ranging from half an hour to several hours, since traditional methods require that each individual injector be separately bled. A large number of engines continue to be manufactured that are not self-bleeding as well as an even larger number of older engines still in use that do not have self-bleeding systems. 
         [0003]    Many users of diesel powered machines do not have the knowledge or experience to bleed their fuel systems. When this becomes necessary, such a user must either bring a mechanic on site or arrange for the machine to be hauled to a mechanic. Even with knowledge of how to bleed a fuel system, accomplishing the actual task may take several hours. 
         [0004]    In any event, bleeding a diesel engine usually is both an enormous inconvenience and also a significant waste of money in lost production time or mileage. At times, such as in military conflicts, taking the time to bleed a diesel engine can be dangerous as well as inconvenient. There is, thus, a long-felt need for a bleeder system that is fast, simple, and economical. 
       SUMMARY OF INVENTION 
       [0005]    The present invention relates generally to an apparatus and method for bleeding diesel fuel powered engines. The apparatus comprises a canister for containing pressurized fuel and having a means for attaching to and engaging with a fuel system. The apparatus may be connected to the inlet side of a fuel filter and, when engaged, will push the fuel into the fuel system and air out of the system without having to separately bleed each injector within the engine. The method generally comprises pressurizing, with air or another suitable gas, a container of fuel; opening the bleed screws of a diesel engine fuel system; and using the pressurized container to flush fuel through the fuel system, thereby driving air out of the fuel system without having to separately bleed each injector within the engine. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0006]      FIG. 1  depicts an exterior view of an embodiment of the inventive bleeder. 
           [0007]      FIG. 2  shows a second embodiment of the inventive bleeder. 
           [0008]      FIGS. 3A and 3B  show a bleed valve for the inventive bleeder in the on and off positions. 
           [0009]      FIGS. 4A and 4B  depict the exterior and a cutaway view of the embodiment of the inventive bleeder depicted in  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Certain embodiments of the novel bleeder  10  are described herein and depicted in  FIGS. 1-4B . 
         [0011]    With reference to  FIG. 2 , bleeder  10  comprises a canister  20 , having a fuel intake  26 , an air intake valve  22 , and a bleed valve  30 . The canister  20  should be manufactured of a material that is safe for storing fuel under pressure. Such materials include aluminum and steel, though other materials may also be appropriate. The canister  20  should be of sufficient size to contain at least enough fuel to bleed the fuel lines of the engine requiring attention. The amount of fuel required will depend on the manufacture of the engine. Generally, engines in farm machinery and heavy duty commercial trucks only require no more than three quarts of fuel to bleed their fuel lines. If the canister  20  is large enough to contain more than the necessary amount of fuel, it may be used more than once to bleed an engine. While it is not necessary to the functionality of the bleeder  10 , the user may prefer the convenience of an incorporated fuel gauge and/or an incorporated pressure gauge for the canister  20 . 
         [0012]      FIGS. 3A and 3B  provide detailed views of the bleed valve  30 . The bleed valve  30  comprises a connector  38  to connect the bleed valve  30  to the canister  20 . The bleed valve  30  further comprises a handle  32  for turning on and off the flow of fuel from the canister  20  into the engine  40 . The handle  32  may be a lever style handle as depicted or may instead be a bar handle, knob, switch, or any other means of controlling the flow of pressurized fuel through the bleed valve  30 . The bleed valve  30  may further comprise a vent tube  34 , which may be placed within the handle as is shown in the depicted embodiment, for directing excess fuel or air from system lines. The bleed valve  30  also comprises a bleed valve nozzle  36  for connecting the bleeder  10  to the primary fuel filter  44  of the engine  40 . 
         [0013]    In order to prepare for use the bleeder  10  as depicted in  FIG. 2 , a user should first ensure that the handle  32  of the bleed valve  30  is set in the off position (detailed drawings of the handle  32  in the on and off positions are shown in  FIGS. 3A and 3B ). Next, the user may remove the fuel cap  28  from the fuel intake  26  and partially fill the canister  20  with fuel of the type required for use by an engine requiring bleeding. To prepare the canister  20  for use, there must only be sufficient room remaining in the canister  20  to allow for pressurization. Once the user has filled the canister  20  with the desired amount of fuel, the user may replace the fuel cap  28  onto the fuel intake  26 . The fuel cap  28  should achieve a secure fit with the fuel intake  26  such that it can withstand pressurization. 
         [0014]    The user may then pressurize the canister by removing the cap  24  from the air intake valve  22  and attaching an air compressor (not shown) to the air intake valve  22 . The user may press a hose fitting of the compressor down onto the stem of the air intake valve  22  and activate the compressor. The amount of air pressure required will depend on the manufacture of the engine requiring bleeding but must, in any event, be greater than the surrounding atmospheric pressure. Generally, a range of 12-18 psi should be sufficient for engines in farm machinery and heavy duty commercial trucks. Since this range of pressure is not dangerous, a pressure relief safety valve is not expected to be necessary, but incorporation of such a valve would be a useful addition. It should be noted that while the method of pressurizing the canister has been described with reference to air, and air is preferred for cost and safety reasons, pressurization could be achieved using any gas that would not be dangerous in combination with fuel and diesel engines. Preferably a substantially non-flammable gas that has been rated as non-flammable/non-toxic will be used; and pre-pressurized canisters of air or other gas may be utilized rather than attaching an air or other gas compressor. 
         [0015]    With reference to  FIG. 1 , in order to use the bleeder  10  to bleed the fuel lines of an engine  40  from air, the user should first open the bleed screws (not shown) on top of the fuel filters  44 ,  48  as well as the bleed screws (not shown) on the fuel injection pump  41 . (A “bleed screw” is a device used to create a temporary opening in an otherwise closed system, which facilitates the removal of air from the system.) Next, the user should connect the bleeder  10  to the primary fuel filter  44 . Optionally, this may be accomplished by connecting the bleed valve nozzle  36  directly to the primary fuel filter  44  but alternatively a less direct attachment, such as to a supply fuel line  52  feeding the primary filter  44 , may be utilized. The bleed valve nozzle  36  should be appropriately sized to fit with the inlet valve (not shown) on the primary fuel filter  44  or to the hose comprising the supply fuel line  52 . 
         [0016]    With reference to  FIGS. 1-3B , when the bleeder  10  has been securely connected to the primary fuel filter  44 , the user may turn the handle  32  on the bleed valve  30  to the “on” position, while preferably taking care to ensure that the vent tube  34  is directed away from the user as a safety precaution. The pressurized fuel flows from the canister  20  along the connector  38 , through the bleed valve  30 , into the supply fuel line  52  and through the primary fuel filter  44 , supply fuel line  52 ′, transfer pump  46 , supply fuel line  52 ″, secondary fuel filter  48 , and supply fuel line  52 ′″, and then throughout the fuel injection pump  41  in the engine  40 , replacing the air in each fuel injection line  43  and fuel injection nozzle  42  within the fuel injection pump  41  with fuel. The air will escape through the bleed screws, and any excess fuel will return to the fuel tank  50  by way of the fuel return line  54 . The user may be able to hear the fuel replacing the air within the system, which is likely to take mere seconds. Of course, the time required for the bleeder  10  to purge trapped air depends on the length and size of fuel system lines between the tank and engine. 
         [0017]    Once an air-free flow of fuel within the fuel lines is evident, the user should turn the handle  32  on the bleed valve  30  to the “off” position. The user may then close the bleed screws. The engine  40  should now be properly bled and ready for operation. The user may wish to refer to starting instructions in the owner&#39;s manual before attempting to start the engine after bleeding the fuel system. 
         [0018]    In certain embodiments of the inventive bleeder  10 , an example of which is depicted in  FIGS. 1 ,  4 A, and  4 B, the bleeder  10  may have two separate canisters  70 ,  80  for air and fuel. The air canister  70  may comprise an air intake valve  72  and an optional pressure gauge  76 . The fuel canister  80  may comprise a fuel intake  82  and a bleed valve  30 . The canisters  70 ,  80  may further comprise optional drains  74 ,  84  to allow a user to release water from the canisters  70 ,  80  in the event that condensation forms due to weather or temperature conditions. The canisters  70 ,  80  may be connected by means of a hollow carrying handle  88 , which serves as both a handle and a tube to allow for transfer of the pressurized air into the fuel canister  80 . In order to pressurize the fuel canister  80 , a user may twist the handle  86  atop the fuel intake  82 . This draws pressurized air from the air canister  70  into the fuel canister  80  by way of the hollow carrying handle  88  and through the air intake valve  72 . The depiction of this embodiment of bleeder  10  further comprises an optional stand  78 . As previously described, the bleeder  10  may then be connected to the fuel system of an engine  40  by engaging the bleed valve  30  to the primary fuel filter  44 . 
         [0019]    In certain embodiments of the inventive bleeder  10 , the bleeder  10  may further include means to heat the bleeder  10 . Diesel fuel contains wax that normally is liquid in the fuel but may solidify at lower temperatures, causing the fuel to become cloudy when temperatures drop, with little crystals of wax that may clog a fuel filter. In even lower temperatures, the fuel may gel so that it will not flow. The bleeder  10  may be equipped with a battery heater on the exterior of the canister or an in-tank fuel warmer. 
         [0020]    The foregoing details are exemplary only. Other modifications that might be contemplated by those of skill in the art are within the scope of this invention, and are not limited by the examples illustrated herein.