Abstract:
A fuel primer is disclosed. The primer includes a rigid valve body having first and second ends with first and second check valves therein. The pump also includes an elastic and substantially fuel impermeable bulb substantially encasing the rigid valve body and sealing to the valve body proximate the first and second check valves.

Description:
FIELD OF THE INVENTION 
       [0001]    This disclosure is related to fuel systems in general and, more particularly, to priming bulbs for fuel systems. 
       BACKGROUND OF THE INVENTION 
       [0002]    Fuel lines or hoses may have a need to be primed, or pre filled, before they may be used for reliable fuel delivery, either by pumping or engine vacuum. One type of device useful for priming fuel lines is a hand-operated primer bulb or pump. Primer bulbs may be molded using Epichlorohydrin (ECO) elastomers which have sufficient elongation to permit de-molding from mold cores. ECO has moderate resistance to fuel but poor fuel vapor permeation. 
         [0003]    What is needed is a device for addressing the above, and related, issues. 
       SUMMARY OF THE INVENTION 
       [0004]    The invention of the present disclosure, in one aspect thereof, comprises a fuel primer. The primer includes a rigid valve body having first and second ends with first and second check valves therein. The pump also includes an elastic and substantially fuel impermeable bulb substantially encasing the rigid valve body and sealing to the valve body proximate the first and second check valves. The bulb may be made from a fluoroelastomer. 
         [0005]    In some embodiments, the rigid valve body provides first and second fuel hose fittings on the first and second ends thereof, respectively, and the rigid valve body directs fuel flow from and to first and second hose fittings to the first and second check valves, respectively. In some embodiments the first check valve allows fuel into the bulb and the second check valve allows fuel out of the bulb. The first fitting may have a larger diameter than the second fitting. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a perspective view of a low permeability fuel primer bulb according to aspects of the present disclosure. 
           [0007]      FIG. 2  is a side cutaway view of the primer bulb of  FIG. 1 . 
           [0008]      FIG. 3  is a transverse cutaway view of the primer bulb of  FIG. 1 . 
           [0009]      FIG. 4  is a view of an engine and fuel supply utilizing a low permeability primer bulb according to aspects of the present disclosure. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0010]    Referring now to  FIG. 1 , a perspective view of a low permeability fuel primer bulb according to aspects of the present disclosure is shown. The device  100  may be considered as a hand-operated fuel pump for priming or filling a fuel hose. From the viewpoint of  FIG. 1 , it can be seen that the primer pump bulb  100  includes a flexible bulb  102 . The bulb  102  may be a fluoroelastomeric material that has a high degree of resistance to permeation by motor fuels and vapors. One example of such a fluoroelastomer is Viton®. The bulb  102  may have one or more ridges  104  or other features to provide a more textured surface for gripping by the user&#39;s hand. 
         [0011]    A first end  106  of the bulb  102  provides a first fuel hose fitting  108 . The first hose fitting  108  proceeds from and is surrounded by a first annulus  110  on the first end  106  of the bulb  102 . A second end  112  of the bulb  102  provides a second fuel hose fitting  114  surrounded by annulus  116 . It will be appreciated that the hose fittings  108 ,  114  may be any type or size of available hose fittings. These include, but are not limited to, press on fittings, clamp fittings, and quick connect fittings. The fittings  108 ,  114  may be constructed from any suitably fuel resistant material including polymers, rubbers, or metals. 
         [0012]    Referring now to  FIG. 2 , a side cutaway view of the primer bulb pump of  FIG. 1  is shown. From the cutaway view, a valve body  202  can be seen and, in the present embodiment, integrates a first check valve  204  and a second check valve  206 . In the present embodiment, the check valves  204 ,  206  are configured within the valve body  202  to allow fuel flow in only one direction from the first end  106  of the bulb  102  to the second end  112 . In the present embodiment, the check valves  204 ,  206  are ball-and-spring type check valves, but other types of check valves may also be utilized. In the present embodiment, the check valves  204 ,  206  are at least partially integrated with the valve body  202 . The check valves  204 ,  206  may have internal components that are retained within the valve body  202  by the respective hose fittings  108 ,  116 . The valve body may be constructed of any suitably fuel resilient material, including polymers, rubbers, and metals. 
         [0013]    In addition to providing a secure attachment point for the check valves  204 ,  206 , the valve body  202  also serves as a resilient and crush resistant member inside the bulb  102 . As will be described in greater detail below, the primer pump bulb  100  may be part of a small engine fuel system, and may have hoses connected at one or both of the hose fittings  108 ,  116 . As such, the primer pump  100  may be subject to bending forces as the attached hoses are coiled for storage. The valve body  202  will prevent the bulb  102  from being kinked, bent, or otherwise damaged when the attached hoses are coiled. 
         [0014]    In operation, the bulb  102  is pressurized on the interior by pressure from a user&#39;s hand on the outside. This pressure will cause fuel to flow through the check valve  206  and out the hose fitting  116 . As pressure is released from the bulb  102 , a vacuum is created in the interior of the bulb, which will tend to draw fuel in through check valve  204  into the interior of the bulb  102 . The cycle will then repeat until the attached hoses are sufficiently primed for operation. It can be seen that the valve body  202  provides a number of holes or perforations  208  that allow fuel to freely flow through one check valve to another via the interior of the bulb  102 . Another function provided by the valve body  202  is to prevent the bulb  102  from being over compressed and collapsing to a state that does not readily return to shape during use. 
         [0015]    From the viewpoint of  FIG. 2 , it can also be seen that relatively few parts are required for assembly of the device  100 . A single component, the valve body  202 , serves as a part of the check valves  204 ,  206  as well as a crush resistant resilient member inside the bulb  102 . In the present embodiment, the springs and balls of the check valves  204 ,  206  fit directly into the ends of the valve body  202 . The hose fittings  108 ,  116  may be ultrasonically welded to the valve body  202  to retain the components of the check valves  204 ,  206 . 
         [0016]    The outer diameter of the valve body  202  near the first end  106  of the device  100  may be slightly larger than the diameter of the valve body  202  near the second end  112  of the device  100 . By constructing the bulb to have a first annulus  110  slightly larger than the second annulus  114 , the bulb  102  may be constructed as a single piece, and fitted to the valve body  102  from the second end to the first end. This also reduces the amount of relatively expensive fluoroelastomeric material needed in the bulb  102 . Producing a bulb having one annulus larger than the other also aids in manufacturing of the bulb itself by reducing the amount of stretch the bulb  102  undergoes when being removed from a mold core. 
         [0017]    Referring now to  FIG. 3 , a transverse cutaway view of the primer bulb of  FIG. 1  is shown. The viewpoint of  FIG. 3  is taken along the section line CC as shown in  FIG. 2 . Here, the fluoroelastomeric bulb  102  can be shown approximately equidistantly surrounding the center of the valve body  202 . Ridges  104  are also shown and are provided for an increased grip of the bulb  100 , particularly in wet environments where the device  100  may be used. 
         [0018]    Referring now to  FIG. 4 , a view of an engine and fuel supply utilizing a low permeability primer bulb pump according to aspects of the present disclosure is shown. The viewpoint  400  of  FIG. 4  illustrates one possible use for the primer bulb pump  100  described herein. A fuel cell  402  may be provided, that may be refillable. A hose  404  may connect the fuel cell  404  to the first end of the primer pump  100 . A second hose  406  may connect the primer pump  100  to an engine or other fuel consumption device. In operation, when the hoses have been attached as shown, the engine  408  may not be able to draw a sufficient amount of fuel from the fuel cell  402  unless the hoses  404 ,  406  are adequately primed with fuel. Activation of squeezing the pump  100  will serve to draw fuel from the fuel cell  402  through the primer pump  100  and to the engine  408 . As previously described, the internal check valves  206 ,  204  serve to fuel to proceed only in one direction from the fuel cell  402  to the engine  408 . 
         [0019]    Thus, the present invention is well adapted to carry out the objectives and attain the ends and advantages mentioned above as well as those inherent therein. While presently preferred embodiments have been described for purposes of this disclosure, numerous changes and modifications will be apparent to those of ordinary skill in the art. Such changes and modifications are encompassed within the spirit of this invention as defined by the claims.