Patent Abstract:
A generator embodying the invention comprises a removable fuel tank that is easily accessible, and may be easily removed from the generator. The generator includes a frame that supports an engine and the fuel tank. The fuel tank is removably interconnected to the frame with at least one quick release fastener. The quick release fastener may include a bolt, a pivoting tab, a clamp, or other similar quick release fasteners. Preferably, the quick release fastener may be engaged by hand, and does not require additional tooling. A fuel line between the fuel tank and the engine includes a quick disconnect attachment that prevents fuel flow and easily detaches the fuel tank from the engine. The fuel tank may be removed from the frame, taken to a gasoline station for refilling, and reattached to the generator for operation.

Full Description:
FIELD OF THE INVENTION 
     This invention relates to engine-driven electrical generators, and more particularly to a fuel tank for such generators. 
     BACKGROUND OF THE INVENTION 
     Electrical generators are commonly used to provide electrical power in situations where conventional wired electrical power grid sources are not available, such as during a power outage, at construction sites, or at remote locations. The generator may use an engine to drive the generator. The generator may include a fuel tank to store gasoline and provide fuel for the engine. Some prior art generators include fuel tanks that are mounted to the generator. 
     When refilling the fuel tank, the operator may take the entire generator to a gasoline station, or a separate gasoline container may be used to transport fuel to the generator. Generators are typically heavy and cumbersome, and transporting the entire generator for a refill is typically not practical. Separate gasoline containers are additional items for an operator to obtain and have available when a refill is necessary. Separate gasoline containers may be easily misplaced and may require additional storage space. 
     Also, the operator may have to maintain each separate gasoline container full of gasoline. It may be desirable for an operator to have a reserve supply of gasoline stored in separate gasoline containers for extended use of the generator. In this situation, the operator may have to make a first trip to the gasoline station with separate gasoline containers to obtain gasoline for filling the generator fuel tank, and a second trip to refill the separate gasoline containers to maintain a reserve supply of gasoline. 
     Some separate gasoline containers may have a capacity that is less than the capacity of the generator fuel tank. For example, some generator fuel tanks have a capacity of 5 gallons, and may have a capacity of 10 gallons or more. A typical separate gasoline container may have a capacity of 2.5 gallons. Therefore, multiple gasoline containers or multiple trips to a gasoline station may be needed to refill the generator. 
     Also, generators are often needed during power outages. Separate gasoline containers may become relatively scarce during a power outage when demand for backup power increases. A shortage of gasoline containers during a power outage may require an operator to have multiple containers or make multiple trips to a gasoline station to maintain a supply of fuel for the generator. The separate gasoline containers also requires extra storage space, and may not be readily available when needed. 
     SUMMARY OF THE INVENTION 
     A generator embodying the invention comprises a removable fuel tank that is easily accessible and may be easily removed from the generator. The exposed, easily accessible, removable fuel tank provides a convenience for the operator because the removable fuel tank may be taken to a gasoline station for refilling, and reattached to the generator for operation. The removable fuel tank is readily available and is less likely to be lost than a separate gasoline container. Additionally, the removable fuel tank does not require additional storage space when not in use. 
     The generator includes a frame that supports an engine and the fuel tank. The engine powers the generator, and the fuel tank stores gasoline for the engine. The fuel tank is removably interconnected to the frame with quick release fasteners. The quick release fasteners may retain the fuel tank to the frame, and may hold the fuel tank and frame from substantially moving with respect to each other. Preferably, the quick release fasteners may be disengaged by hand without the use of additional tooling. A fuel line between the fuel tank and the engine may include a quick disconnect attachment that may shut off fuel flow and easily detach the fuel tank from the engine. 
     In the preferred embodiment, the quick release fastener includes a threaded fastener, such as bolt or screw, and may include a handle to facilitate engaging or disengaging the fastener by hand. The fuel tank may include a clamping portion, and the bolt may extend through a slot in the clamping portion and engage the frame. The bolt may include a disc-shaped flange that clamps the clamping portion to the frame. Alternatively, the quick release fastener may include other fasteners, such as clamps, pivoting tabs, key locks, elastic members, pins, latches, or other similar fasteners. Preferably, the quick release fasteners may be engaged by hand, and do not require a tool. 
     The fuel tank may be openly exposed near the top of the generator to provide easy access when refilling the fuel tank, and when detaching or reattaching the fuel tank. The fuel tank is preferably not enclosed within a housing. The fuel tank is readily available, and the operator does not have to locate a separate gasoline container when the generator requires refueling. The entire removable fuel tank may be refilled without the need for multiple gasoline containers or multiple trips to the gasoline station. 
     Additionally, it may be desirable to maintain a reserve fuel supply for operating the generator for extended periods of time. The operator may make a single trip to the gasoline station to refill the removable fuel tank and separate gasoline containers. With some prior art generators, separate trips to the gasoline station with separate gasoline containers were needed to first obtain gasoline for refilling the generator, and then refill the separate gasoline containers again for a reserve supply of gasoline. With the removable fuel tank, an operator may refill the generator, and refill separate gasoline containers for a reserve fuel supply in a single trip to the gasoline station. Therefore, the removable fuel tank may be particularly useful for initial filling of the fuel tank, and may help an operator to maximize a reserve gasoline supply while minimizing trips to the gasoline station. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a generator having a removable fuel tank, according to the present invention. 
     FIG. 2 is an enlarged view of a quick-disconnect fuel line on the generator of FIG.  1 . 
     FIG. 3 is an exploded view of the fuel tank on the generator of FIG.  1 . 
     FIG. 4 is a cross sectional view taken along line  4 — 4  of FIG.  1 . 
     FIG. 5 is a perspective view of the fuel tank removed from the generator of FIG.  1 . 
     FIG. 6 is an alternate embodiment of a quick release fastener for retaining the fuel tank to the generator. 
     FIG. 7 is an alternate embodiment of a quick release fastener for retaining the fuel tank to the generator. 
     FIG. 8 is an alternate embodiment of a quick release fastener for retaining the fuel tank to the generator. 
    
    
     Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     Although references are made below to directions, such as left, right, up, down, top, bottom, front, rear, back etc., in describing the drawings, they are made relative to the drawings (as normally viewed) for convenience. These directions are not intended to be taken literally or limit the present invention in any form. 
     DETAILED DESCRIPTION 
     FIG. 1 illustrates a portable generator  10  having a removable fuel tank  14 . The generator  10  includes a frame  18  having a base  22 , a support portion  26  disposed above the base  22 , and a frame handle  30  projecting outwardly from the frame  18 . The frame handle  30  may be movable to reduce the height of the generator  10  for storage or transport. Wheels  34  are interconnected to the frame  18  near the base  22  to facilitate transporting the generator  10 . Stops  38  are also connected to the frame  18  near the base  22  to help provide stability while the generator  10  is stationary. FIG. 1 illustrates a portable generator  10  having wheels  34 , but the removable fuel tank  14  may also be used with a stationary generator. The removable fuel tank  14  may be beneficial for a stationary generator since the entire stationary generator cannot be transported to refill the fuel tank  14 . 
     An engine  42  is connected to the frame  18  and supported by the base  22 . The engine  42  is generally disposed between the base  22  and the support portion  26 . In the illustrated embodiment, the engine  42  is an approximately 10 HP engine, and the fuel tank  14  stores fuel for the engine  42 . The fuel tank  14  is disposed above engine  42 , and is openly exposed near the top of the generator  10  to provide easy access to the fuel tank  14 . The generator  10  includes a gen-set  46  that generally convert mechanical power from the engine  42  into electrical current. The gen-set  46  may provide AC or DC current, and may include, among other things, a rotor, stator, or alternator. 
     As shown in FIG. 1, the generator  10  includes a control panel  50 , having several electrical outlets. Various tools or appliances may be plugged into the control panel  50 , and the generator  10  may provide power for the tools or appliances. In the preferred embodiment, the generator  10  provides an AC current of 105-125 Volts (V), 50-60 Hertz (Hz), and 20 Amps (A) through a conventional outlet in the control panel  50 . Alternatively, the generator  10  may include a 120V-15A outlet, a 120V-30A locking type outlet, a 120/240V-20A locking type outlet, a 120/240V-30A locking type outlet, a 12V DC current outlet, or other similar outlets known to one skilled in the art. 
     The fuel tank  14  is removably interconnected to the frame  18  near the support portion  26 . A quick release fastener  54  retains the fuel tank  14  to the frame  18 . In the illustrated embodiment, the fuel tank  14  may have a capacity of approximately 5 gallons or more. The fuel tank  14  may be formed from a plastic material, or another similar substantially rigid material that is resistant to gasoline. The fuel tank  14  has a first face  58  that is substantially rectangular, a second face  62 , and a wall  66  extending between the first face  58  and the second face  62 . The first face  58  faces away from the engine  42 , and the second face  62  faces toward the engine  42 . 
     The wall  66  has a first end  70  and a second end  74  disposed opposite one another. The wall  66  also includes a first side  78  and a second side  82  disposed opposite one another, and adjacent the first end  70  and second end  74 . In the illustrated embodiment, the first end  70  is located near the frame handle  30 , and includes a C-shaped tank handle  86 . The second end  74  is disposed opposite the first end  70  near the control panel  50 , and includes a ridge  88  that extends inwardly from the second end  74 . The tank handle  86  and ridge  88  facilitate carrying the fuel tank  14  when the fuel tank  14  is removed from the frame  18 . 
     The fuel tank  14  includes a fuel opening  90  for refilling the fuel tank  14 . In FIG. 1, the fuel opening  90  is located in the first face  58  near the top of the generator  10 . The first face  58  and the fuel opening  90  are exposed near the top of the generator  10  to make the fuel opening  90  easily accessible. A fuel cap  92  may detachably engage the fuel opening  90  to enclose the fuel opening  90 . In the illustrated embodiment, the fuel cap  92  may be threaded on and off of the fuel opening  90 . The fuel cap  92  may include a vent  94  to release pressure within the fuel tank  14 . Vapors within the fuel tank  14  may expand when the fuel tank  14  is sealed, and actuating the vent  94  to release pressure may help prevent removing the fuel cap  92  while the contents of the fuel tank  14  are under pressure. 
     The fuel tank  14  includes a clamping portion  96 , and the frame  18  includes a retaining surface  98 . In the illustrated embodiment, the support portion  26  includes elongated rods  102 , and the retaining surface  98  is located near the top of the elongated rods  102 . The clamping portion  96  is located adjacent the sides  78 ,  82  of the fuel tank  14 . The retaining surface  98  is adjacent the clamping portion  96  when the fuel tank  14  is interconnected to the frame  18 , and the retaining surface  98  may contact the clamping portion  96 . The clamping portion  96  may be incorporated into an edge  106  extending along the sides  78 ,  82  of the fuel tank  14 , and the fuel tank  14  may extend outwardly beyond the elongated rods  102 . The quick release fastener  54  holds the retaining surface  98  and clamping portion  96  from substantially moving with respect to each other. 
     The fuel tank  14  may include a recess  110  in the sides  78 ,  82  that extends inwardly toward the fuel tank  14 . As shown in FIG. 1, two recesses  110  extend into each side  78 ,  82 . The clamping portion  96  may be at least partially disposed within the recess  110 . A slot  114  extends into the clamping portion  96  within the recess  110 . The quick release fastener  54  extends through the slot  114  and engages the frame  18  to retain the fuel tank  14  to the frame  18 . 
     FIG. 3 illustrates the fuel tank  14  removed from the frame  18 . In the illustrated embodiment, the quick release fasteners  54  are bolts  118  having a threaded end  122  and a head  126  opposite the threaded end  122 . A disc-shaped flange  130  projects radially outwardly from the bolt  118  adjacent the threaded end  122 . The head  126  includes a wing handle  134  to facilitate tightening and loosening the bolt  118  by hand. In FIG. 3, the fuel tank  14  includes four bolts  118 , one for each recess  110 . The recesses  110  provide clearance to rotate and thread the bolts  118  into position, and reduce the overall height of the fuel tank frame assembly. The recesses  110  and bolts  118  are preferably located near the corners of the fuel tank  14  to evenly distribute support for the fuel tank  14 . In the illustrated embodiment, the fuel tank  14  also includes an indentation  138  in the first side  78  between the other recesses  110 . The indentation  138  may provide access to the engine  42  for maintenance purposes, such as checking and refilling oil in the engine  42 . 
     The bolts  118  threadedly engage the support portion  26  to retain the fuel tank  14  to the frame  18 . As shown in FIG. 3, the support portion  26  includes elongated rods  102 , and the retaining surface  98  is disposed near the top of the elongated rods  102 . In the illustrated embodiment, apertures  142  extend into the elongated rods  102 . The apertures  142  are aligned with the slots  114 , and the bolts  118  extend through the slots  114  and into the apertures  142 . In FIG. 4, inserts  146  are disposed within the apertures  142 , and have a threaded inner surface  150 . The threaded end  122  of the bolt  118  engages the inner surface  150  of the insert  146 . An air gun having a threaded attachment that engages the insert&#39;s threads is used to form flanges on the inserts  146 . Alternatively, the threaded end  122  of the bolt  118  may directly engage the support portion  26 . 
     The wing handle  134  permits the bolt  118  to be easily threaded in or out of the apertures  142 . Preferably, the bolt  118  may be threaded by hand, and no additional tools are needed to insert or remove the bolt  118 . As shown in FIG. 4, the clamping portion  96  is clamped between the disc flange  130  and the elongated rod  102  when the bolt  118  is tightened. The bolt  118  retains the fuel tank  14  to the frame  18 , and holds the retaining surface  98  and clamping portion  96  from substantially moving with respect to each other. 
     As shown in FIG.  3  and mentioned above, the fuel tank  14  includes the ridge  88  near the first end  70  and the tank handle  86  near the second end  74 . The ridge  88  and tank handle  86  provide surfaces for an operator to grip while removing the fuel tank  14  from the frame  18 . The fuel tank  14  may be removed from the frame  18  after the quick release fasteners  54  are disengaged. 
     In FIG. 2, a fuel line  154  is connected to the fuel tank  14  and carries fuel from the fuel tank  14  to the engine  42  (FIG.  1 ). The fuel line  154  may include a shut-off valve  158  and a quick disconnect  162 . The shut-off valve  158  may be actuated to stop fuel flow. Once the fuel flow is stopped, the quick disconnect  162  may be disengaged to disconnect the fuel line  154 , and the fuel tank  14  may be removed from the frame  18 . 
     In the illustrated embodiment, the quick disconnect  162  includes a plug  166  that may be inserted into a receptacle  170 . The receptacle  170  may include a biased clamp  178  that clamps the plug  166  in an engaged position. The plug  166  may include an O-ring or gasket to help seal the fuel line  154 . The biased clamp  178  may be actuated against the bias to unclamp the plug  166 . Once the plug  166  is unclamped, the plug  166  may be detached from the receptacle  170  and moved to a disengaged position. In FIG. 2, the solid lines illustrate the plug  166  in the engaged position, and the broken lines illustrate the plug  166  in the disengaged position. 
     The fuel tank  14  may be removed from the frame  18  when the quick release fasteners  54  are disengaged, the shut-off valve  158  stops fuel flow, and the quick disconnect  162  of the fuel line  154  is disconnected. As mentioned above and illustrated in FIG. 3, the tank handles  86  and ridge  88  facilitate lifting the fuel tank  14  and removing the fuel tank  14  from the frame  18 . 
     FIG. 5 illustrates an operator holding the tank handle  86  and carrying the fuel tank  14 . FIG. 5 also illustrates the second face  62  having a rib  182  integrally formed with the fuel tank  14 . As mentioned above, the fuel tank  14  may be formed from a plastic material, and the rib  182  may help provide strength and stability for the fuel tank  14 . In the illustrated embodiment, the rib  182  projects outwardly from the fuel tank  14  and extends in a V-shape along the second face  62 . The rib  182  may also extend from the V-shape towards the tank handle  86  along the second face  62  for additional stability. FIG. 5 also illustrates the shut-off valve  158  and receptacle  170  of the fuel line  154  interconnected to the second end  74  of the fuel tank  14 . 
     Since the fuel tank  14  is removable, the fuel tank  14  may be transported separately from the generator  10 . In some prior art generators, a separate gasoline container may be needed to transport fuel from a gas station to the generator and refill the fuel tank. With this prior art arrangement, gasoline is transferred from the gas pump at the gasoline station to the separate gasoline container, and then transferred from the separate gasoline container to the generator. Each transfer or pour between containers provides an additional risk of spilling the gasoline. The separate gasoline container also requires extra storage space, and may not be readily available when needed. 
     As shown in FIGS. 1,  3  and  4 , the quick release fastener  54  includes the bolt  118 . Other embodiments of the quick release fastener  54  may also be used to retain the fuel tank  14  to the frame  18 . As shown in FIG. 6, the quick release fastener  54  includes a relatively flat tab  210  that retains the fuel tank  14  to the frame  18 . The tab  210  is pivotally connected to the frame  18  and projects outwardly from the support portion  26 . The tab  210  is connected to the support portion  26 , and may pivot with respect to the frame  18  to engage or disengage the fuel tank  14 . The fuel tank  14  includes at least one recess  110  that extends inwardly toward the fuel tank  14 . A clamping portion  218  is at least partially disposed within the recess  110 , and a slot  222  extends into the clamping portion  218  within the recess  110 . The recess  110  and tab  210  shown in FIG. 6 may be located on the generator  10  (FIG. 1) similarly to the location of the recesses  110  and quick release fasteners  54  shown in FIGS. 1 and 3. 
     In FIG. 6, when connecting the fuel tank  14  to the frame  18 , the fuel tank  14  is positioned above the support portion  26  such that the slots  222  are aligned with the tabs  210 . The tabs  210  are pivoted to extend in the same direction as the slots  222 . The fuel tank  14  is placed on the support portion  26  and the tabs  210  extend through the slots  222 . The tabs  210  are in a disengaged position when the tabs  210  are aligned with the slots  222 , and the tabs  210  extend in the same direction as the slots  222 . The clamping portion  218  may contact a retaining surface  226  on the support portion  26 . Once the tabs  210  extend through the slots  222 , the tabs  210  may be pivoted 90 degrees from the disengaged position to an engaged position to clamp the clamping portion  218  to the support portion  26  and retain the fuel tank  14  to the frame  18 . FIG. 6 illustrates the tab  210  in the engaged position. 
     The clamping portion  218  may include nubs  230  that project from the clamping portion  218  adjacent the slot  222 . The nubs  230  may lock the tab  210  into the engaged position as the tab  210  is pivoted with respect to the slot  222 . The nubs  230  may be aligned approximately normal to the slot  222 , and the tab  210  may slightly deflect the nubs  230  as the tab  210  is rotated 90 degrees and locked into the engaged position. The tab  210  may be spring-loaded to enable it to clear the nubs  230 . The nubs  230  may resist movement of the tab  210  from the engaged position to the disengaged position. The tab  210  holds the retaining surface  226  and clamping portion  218  from substantially moving with respect to each other. 
     To remove the fuel tank  14  from the frame  18 , the tabs  210  are pivoted to the disengaged position to align the tabs  210  with the slots  222 . The quick disconnect  162  (FIG. 2) is disengaged to disconnect the fuel tank  14  from the frame  18 . The fuel tank  14  may then be removed from the frame  18 . 
     FIG. 7 illustrates a variation of the embodiment shown in FIG.  6 . In FIG. 7, the fuel tank  14  extends over the elongated rods  102  of the frame  18 , and includes at least one recess  110  that provides clearance for the quick release fastener  54 , which includes the tab  210 . Once again, the tab  210  may pivot with respect to the frame  18  to engage or disengage the fuel tank  14 . A clamping portion  310  is at least partially disposed within the recess  110 , and the clamping portion  310  includes an elongated slot  314 . Similar to the previously described embodiment, the fuel tank  14  is initially positioned on the support portion  26  such that the slots  314  are aligned with the tabs  210 . 
     In the illustrated embodiment, the slot  314  is enclosed within the clamping portion  310 , and the slot  314  extends in substantially the same direction as the elongated rod  102 . Alternatively, the slots  414  could extend in any direction relative to the elongated rod  102 , as long as the tab  210  may be aligned with the slot  314 . Once the fuel tank  14  is positioned on the support portion  26  and the tab  210  extends through the slot  314 , the tab  210  may be pivoted 90 degrees from the disengaged position to the engaged position to clamp the clamping portion  310  and retain the fuel tank  14  to the frame  18 . FIG. 7 illustrates the tab  210  in the engaged position. 
     As described above, the clamping portion  310  may include nubs  318  that project from the clamping portion  310  adjacent the slot  314 . The nubs  318  may lock the tab  210  into an engaged position as the tab  210  is pivoted with respect to the slot  314 . Tab  210  may be spring-loaded to enable it to clear nubs  318 . The support portion  26  includes a retaining surface  322 , and the tab  210  holds the retaining surface  322  and clamping portion  310  from substantially moving with respect to each other. To remove the fuel tank  14 , the tabs  310  are pivoted to the disengage position and aligned with the slots  414 , and the quick disconnect  162  (FIG. 3) is disengaged. The fuel tank  14  may then be removed from the frame  18 . 
     FIG. 8 illustrates another alternate embodiment of the quick release fastener  54  that includes a C-shaped clamp  410  that retains the fuel tank  14  to the frame  18 . The fuel tank  14  includes a flange  414  that projects outwardly from the fuel tank  14  and extends along the sides  78 ,  82  of the fuel tank  14 . The support portion  26  includes a lip  418  that is adjacent to the flange  414  when the fuel tank  14  is retained to the frame  18 . The flange  414  includes a clamping portion  422 , and the lip  418  includes a retaining surface  426 . The clamp  210  is engaged to clamp the flange  414  to the lip  418  and retain the fuel tank  14  to the frame  18 . The clamp  410  holds the retaining surface  426  and clamping portion  422  from substantially moving with respect to each other. The clamp  410  may be disengaged from the flange  414  to remove the fuel tank  14  from the frame  18 . 
     One skilled in the art will recognize that many variations of these illustrated embodiments of quick release fasteners  54  may be implemented to retain the removable fuel tank  10  to the frame  18 . For example, the quick release fasteners  54 , bolts  118  and tabs  210  (FIGS. 3-4 and  6 - 7 ) may be adapted to engage with an aperture in the flange  414  (FIG.  8 ). Additionally, the flange  414  (FIG. 8) may be combined with the support portion  26  having the elongated rod  112  (FIGS. 3-4 and  6 - 7 ) or the lip  418  (FIG.  8 ). Similarly, the lip  418  (FIG. 8) may also be combined with the recess  110  (FIGS. 3-4 and  6 - 7 ) and quick release fastener  54 . These and other similar embodiments of quick release fasteners  54  may be used to retain the fuel tank  14  to the frame  18 . 
     The foregoing detailed description describes only a few of the many forms that the present invention can take, and should therefore be taken as illustrative rather than limiting. It is only the following claims, including all equivalents that are intended to define the scope of the invention.

Technology Classification (CPC): 5