Abstract:
A fuel bladder apparatus includes a fuel bladder, tank, and cap. The fuel bladder includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, inlet port, outlet port, and air inlet. The inlet port is disposed in cooperative alignment with the fuel inlet. The fuel inlet is sealed to the inlet port. The outlet port is disposed in cooperative alignment with the fuel outlet. The cap is detachably secured to the inlet port. The cap detachably seals the fuel inlet.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to a fuel bladder apparatus and method. More particularly, the present invention pertains to a low permeability fuel bladder to store and provide fuel for an engine and method for storing and providing fuel for an engine. 
       BACKGROUND OF THE INVENTION 
       [0002]    Fuel burning engines are utilized to provide power in a vast array of applications. Generally, a fuel tank is utilized to store and provide a ready supply of fuel for the engine. Typically, the fuel tank is a container with relatively rigid sides of metal or plastic and a cap that is removed to fill the fuel tank. The cap is vented to allow air into the tank. In use, as fuel is drawn out of the tank to be combusted in the engine, the volume of fuel removed is displaced by fuel vapor and air drawn in through the vent in the cap. Without this venting, a partial vacuum may form in the tank and fuel may cease to flow to the engine. Unfortunately, the vented cap also allows fuel vapor to escape into the environment. 
         [0003]    To reduce this escape of fuel, some conventional tank systems employ a carbon filter in line with a tank vent to absorb fuel vapors. For example, carbon filters have been utilized in the automotive industry with some success. Compared to the cost of a automobile, the added cost of a carbon filter or vapor recovery system is relative low. However, compared to the cost of most yard equipment, the added cost of a carbon filter may be relatively expensive. In addition, although a carbon filter reduces pollution that results from fuel vapors escaping from the tank out into the environment via permeation or effusion through the wall of the fuel tank, to re-fill the tank, the cap is opened and, as fuel is poured into the fuel tank, the fuel vapor in the tank is displaced by the added volume of fuel and expelled from the inlet. 
         [0004]    Accordingly, it is desirable to provide a method and apparatus capable of overcoming the disadvantages described herein at least to some extent. 
       SUMMARY OF THE INVENTION 
       [0005]    The foregoing needs are met, to a great extent, by the present invention, wherein in one respect a fuel bladder to store and provide fuel for an engine and method for storing and providing fuel for an engine is provided. 
         [0006]    An embodiment of the present invention pertains to a fuel bladder apparatus. The fuel bladder apparatus includes a fuel bladder, tank, and cap. The fuel bladder includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, inlet port, outlet port, and air inlet. The inlet port is disposed in cooperative alignment with the fuel inlet. The fuel inlet is sealed to the inlet port. The outlet port is disposed in cooperative alignment with the fuel outlet. The cap is detachably secured to the inlet port. The cap detachably seals the fuel inlet. 
         [0007]    Another embodiment of the present invention relates to an apparatus for supplying fuel to a yard equipment engine. The apparatus includes a means for disposing a fuel bladder in a tank and means for sealing the fuel inlet to the inlet port to generate a fuel bladder volume and a tank volume. The means for disposing a fuel bladder in a tank includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, an inlet port, outlet port, and air port. The inlet port is disposed in cooperative alignment with the fuel inlet. The outlet port is disposed in cooperative alignment with the fuel outlet. The fuel bladder volume is fluidly isolated from the tank volume. The tank volume is in fluid connection with the atmosphere via the air port. Air from the atmosphere enters the tank volume via the air port in response to fuel being removed from the fuel bladder and air. 
         [0008]    Yet another embodiment of the present invention pertains to a method of supplying fuel to a yard equipment engine. In this method a fuel bladder is disposed in a tank. The fuel bladder includes an elastomeric envelope, fuel inlet, and fuel outlet. The elastomeric envelope has an upper section, lower section and side section. The fuel inlet is disposed at the upper section. The fuel outlet is disposed at the lower section. The tank includes a rigid housing, inlet port, outlet port and air port. The inlet port is disposed in cooperative alignment with the fuel inlet. The outlet port is disposed in cooperative alignment with the fuel outlet. The fuel inlet is sealed to the inlet port to generate a fuel bladder volume and a tank volume. The fuel bladder volume is fluidly isolated from the tank volume. The tank volume is in fluid connection with the atmosphere via the air port. Air from the atmosphere enters the tank volume via the air port in response to fuel being removed from the fuel bladder and air. 
         [0009]    There has thus been outlined, rather broadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
         [0010]    In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
         [0011]    As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  is a partial cut-away side view of a fuel tank and fuel bladder according to an embodiment of the invention and an engine suitable for use with the fuel tank. 
           [0013]      FIG. 2  is a cut-away view of the fuel tank and fuel bladder of  FIG. 1  in a filled condition. 
           [0014]      FIG. 3  is a cut-away view of the fuel tank and fuel bladder of  FIG. 1  in a partially filled condition. 
           [0015]      FIG. 4  is a cut-away view of the fuel tank and fuel bladder of  FIG. 1  in an empty condition. 
           [0016]      FIG. 5  is a cut-away view of a fuel tank and fuel bladder according to another embodiment. 
           [0017]      FIG. 6  is a partial cut-away view of the fuel tank and fuel bladder according to  FIG. 5  in a partially filled condition. 
           [0018]      FIG. 7  is a cut-away view of a fuel tank and fuel bladder according to another embodiment. 
           [0019]      FIG. 8  is a partial cut-away view of the fuel tank and fuel bladder according to  FIG. 7  in a partially filled condition. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    Preferred embodiments of the invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. As shown in  FIG. 1 , a power unit  10  includes an engine  12  and a fuel apparatus  14 . In a preferred embodiment, the engine  12  is an internal combustion engine that utilizes any suitable fuel such as gas, diesel, and/or other such liquid fuel. In a particular example, the engine  12  is suitable for use to power yard equipment such as a lawn mower, tiller, chipper, snow blower, power washer, or the like. The fuel apparatus  14  is configured to store and/or supply the fuel to the engine  12 . In one example of a preferred embodiment, the fuel apparatus  14  includes a fuel bladder  16  and tank  18 . 
         [0021]    In general, the fuel bladder  16  includes an envelope or container that is compatible with fuel and is impermeable or has a low fuel permeability. In various embodiments, the fuel bladder  16  may include any suitable flexible or elastomeric material. Examples of suitable elastomeric materials includes rubber, poly tetra fluoro ethylene (“PTFE”), poly ether ether ketone (“PEEK”), thermoplastic urethane, and the like. The elastomeric material may be utilized alone or as a coating. In a particular example, the fuel bladder  16  may include a rubber or polymer coated fabric. Rubber or polymer coated fabric may provide improved abrasion resistance as compared to fuel bladders without fabric reinforcement. The fuel bladder  16  includes a fuel inlet  20  and fuel outlet  22 . The fuel inlet  20  is configured to receive fuel that is poured or otherwise introduced to the fuel bladder  16 . When not actively being filled, the fuel inlet  20  may be sealed via a cap  24 . The fuel outlet  22  is disposed to draw fuel out of the fuel bladder  16 . In a particular example, the fuel outlet  22  is disposed at a low portion or bottom of the fuel bladder  16 . 
         [0022]    The tank  18  may be a relatively rigid housing or container to protect the fuel bladder  16 , contain leaked fuel in the event of damage to the fuel bladder  16 , and/or secure the fuel apparatus  14  to the engine  12 . To this end, the tank  18  may be fabricated from any suitable material such as, for example, metal, plastic, or the like. The tank  18  includes an inlet port  26 , outlet port  28 , and air port  30 . The inlet port  26  is secured or affixed to the fuel inlet  20 . For example, the inlet port  26  may be secured to the fuel inlet  20  by an adhesive and/or mechanical fastener. The outlet port  28  provides access to the fuel outlet  22  and/or an opening through which a fuel line  32  may fluidly connect the fuel bladder  16  to the engine  12 . The air port  30  is configured to facilitate an ingress and egress of air into and out of the tank  18 . That is, the air port allows and essentially free exchange of air into and out of the tank  18 . It is an advantage of various embodiments of the invention that fuel and fuel vapors are essentially prevented from escaping into the environment during this free exchange of air. That is, due to the fuel bladder  16 , the tank  18  is divided into two distinct volumes, for example, a free tank volume  34  and a bladder volume  36 . As fuel from the fuel bladder  16  is utilized by the engine  12 , the bladder volume  36  is reduced. Air enters the free tank volume  34  via the air port  30  to offset the reduction in the bladder volume  36 . Conversely, in response to an increase in the bladder volume  36 , air may exit the air port  30 . For example, in response to introducing fuel to the fuel bladder  16  via the fuel inlet  20 , the bladder volume  36  may increase and the free tank volume  34  may decrease as air exits via the air port  30 . In this manner, the air port  30  facilitates an ambient pressure equilibrium in the tank  18  acting upon the fuel bladder  16 . 
         [0023]      FIG. 2  is a cut-away view of the tank  18  and fuel bladder  16  of  FIG. 1  in a filled condition. As shown in  FIG. 2 , the fuel bladder  16  essentially fills the tank  18  and the free tank volume  34  is relatively small. Also shown in  FIG. 2 , the air port  30  may include a cover or other such structure to reduce the inflow of contaminants such as, for example, dirt, water, insects, etc. In other examples, the air port  30  may include a filter such as, fabric, fibers, or the like, to reduce the inflow of contaminants into the free tank volume  34 . 
         [0024]      FIG. 3  is a cut-away view of the tank  18  and fuel bladder  16  of  FIG. 1  in a partially filled condition. As shown in  FIG. 3 , the partially filled fuel bladder  16  occupies relatively less of the tank  18  than the filled fuel bladder  16  shown in  FIG. 2 . In addition, the free tank volume  34  is relatively greater than shown in  FIG. 2 . According to another embodiment, the air port  30  may be disposed near or integrated into the inlet port  26 . It is an advantage of this embodiment that the cap  24  may partially cover the air port  30  and thereby reduce inflow of contaminants into the free tank volume  34 . 
         [0025]      FIG. 4  is a cut-away view of the tank  18  and fuel bladder  16  of  FIG. 1  in an empty condition. As shown in  FIG. 4 , the essentially empty fuel bladder  16  occupies relatively less of the tank  18  than the filled or partially filled fuel bladder  16  shown in  FIGS. 2 and 3 . In addition, the free tank volume  34  is relatively greater than shown in  FIGS. 2 and 3 . According to another embodiment, the air port  30  may be disposed near or integrated into the inlet port  26 . It is an advantage of this embodiment that the cap  24  may partially cover the air port  30  and thereby reduce inflow of contaminants into the free tank volume  34 . 
         [0026]      FIG. 5  is a cut-away view of a tank  18  and fuel bladder  16  according to another embodiment. As shown in  FIG. 5 , the inlet port  26  includes an inlet tube  38  that extends into the tank  18 . According to this embodiment, the fuel bladder  16  expands and contracts by sliding along this inlet tube. The fuel bladder  16  includes a series of pleats  40 , a float  42 , and a seal  44 . 
         [0027]    The pleats  40  facilitate expansion and contraction of the fuel bladder  16 . For example, in a manner similar to the pleats in a bellows, the pleats  40  facilitate an orderly and efficient contraction and expansion of the fuel bladder  16 . 
         [0028]    The float  42  provides buoyancy to the top of the fuel bladder  16  in order to keep the top of the fuel bladder  16  floating above any fuel present in the fuel bladder  16 . In this regard, the density of the float  42  is relatively less than that of fuel. For example, the float  42  may include air, foam, or the like. 
         [0029]    The seal  44  is disposed at an interface between the inlet tube  38  and the float  42 . The seal  44  translates along the inlet tube  38 . The seal  44  may provide a substantially fuel impermeable or fuel resistant interface to reduce leakage of fuel from the fuel bladder  16  into the free tank volume  34  and/or out of the tank  18 . 
         [0030]    The fuel bladder  16  shown in  FIG. 5  is essentially full of fuel, for example. Accordingly, the free tank volume  34  is relatively small. As shown in  FIG. 6 , the fuel bladder  16  is substantially empty. As such, the pleats  40  are shown in a relatively compressed state, the bladder volume  36  is relatively low, and the free tank volume  34  is relatively high. 
         [0031]      FIG. 7  is a cut-away view of a tank  18  and fuel bladder  16  according to another embodiment. As shown in  FIG. 7 , the fuel apparatus  14  may be curved, rounded, or the like. In a particular example, the tank  18  may include a clamshell or clamshell-like shape and the fuel bladder  16  may be configured to substantially fill the tank  18  when full. It is an advantage of this embodiment that the fuel bladder  16  collapses or “pancakes” down upon itself readily. As such, the fuel bladder  16  may modulate according to the bladder volume  36  without the need for pleats. 
         [0032]    In addition, the fuel apparatus  14  optionally includes a gasket  46  to seal the fuel inlet  20  and/or the inlet port  26 . If present, the gasket  46  may include an elastomeric material disposed between the cap  24  and the fuel inlet  20  and/or the inlet port  26 , for example. In a particular example, the gasket  46  maybe affixed to the underside of the cap  24  and configured to engage the inlet port  26  in response to securing the cap  24  to the inlet port  26 . 
         [0033]      FIG. 8  is a partial cut-away view of the tank  18  and fuel bladder  16  according to  FIG. 7  in an essentially empty condition. As shown in  FIG. 8 , the fuel bladder  16  essentially collapses upon itself in an efficient manner. As such, substantially all or most of the fuel from the fuel bladder  16  may be utilized by the engine  12  shown in  FIG. 1 . In addition, the fuel bladder  16  readily expands in response to the addition of fuel e.g., by pouring fuel into the fuel inlet  20 . 
         [0034]    The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.