Abstract:
A vocational truck vehicle has a vocational body mounted on a chassis rearward of a cab and overlying at least one rear axle. A fuel storage module for storing fuel for use by an alternative-fueled combustion engine which propels the vehicle has a frame holding at least one fuel storage vessel and attached to the vocational body to locate the fuel storage module in confronting relation to a rearward-facing wall of the vocational body.

Description:
REFERENCE TO RELATED APPLICATION AND PRIORITY CLAIM 
       [0001]    This application claims the priority of Provisional Patent Application No. 61/595,022, filed on 03 Feb. 2012, the entire content of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD  
       [0002]    This disclosure relates to vehicles which are propelled by combustion engines, particularly to fuel storage in a truck vehicle whose propulsion engine is fueled by an alternative fuel, such as compressed natural gas (CNG). 
       BACKGROUND  
       [0003]    Gasoline and diesel fuel are historically considered conventional fuels for motor vehicles of various types. On-board storage of such liquid fuels is typically in one or more fuels tanks mounted on a chassis of a vehicle. 
         [0004]    Alternative energy sources for operating certain motor vehicles are in use. One example of an alternative energy source is compressed natural gas (CNG). On-board storage requirements for CNG are considerably different than those for gasoline and diesel fuel. Natural gas is stored in a compressed state at pressure which is much greater than atmospheric pressure within a storage volume which is sufficient to provide a vehicle such as a large commercial truck with an acceptable driving range comparable to that obtained in vehicles using gasoline or diesel fuel. 
       SUMMARY OF THE DISCLSOURE  
       [0005]    The present disclosure relates to a vocational truck vehicle comprising a cab-chassis having a chassis, a cab mounted on the chassis at a front of the vocational truck vehicle, the chassis including at least one rear axle rearward of the cab and a combustion engine for propelling the vocational truck vehicle. 
         [0006]    A vocational body is mounted on the chassis rearward of the cab, overlying the at least one rear axle. The vocational body has a rearward-facing wall. 
         [0007]    A fuel storage module for storing fuel for use by the combustion engine comprises a frame which holds at least one fuel storage vessel and is attached to the vocational body to locate the fuel storage module in confronting relation to the rearward-facing wall of the vocational body. 
         [0008]    The foregoing summary, accompanied by further detail of the disclosure, will be presented in the Detailed Description below with reference to the following drawings that are part of this disclosure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a perspective view of a waste collection vehicle showing front, top, and left side. 
           [0010]      FIG. 2  is a perspective view of the waste collection vehicle of  FIG. 1  showing top, left side, and rear. 
           [0011]      FIG. 3  is an enlarged perspective view of a tailgate at the rear of the waste collection vehicle of  FIG. 2 . 
           [0012]      FIG. 4  is an exploded perspective view of the tailgate. 
           [0013]      FIG. 5  is an enlarged fragmentary view of a portion of  FIG. 4 . 
           [0014]      FIG. 6  is a schematic diagram. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]      FIG. 1  shows one example of a vocational truck vehicle  10 , a front loading waste collection vehicle  10 , having an alternative fuel system, meaning a fuel system which is neither gasoline nor diesel. 
         [0016]    Truck vehicle  10  comprises a cab-chassis having a chassis  11  and a cab  33  mounted on chassis  11  at the front of truck vehicle  10 . Chassis  11  comprises various components, including a frame, an engine, a suspension, front steered road wheels  11 A, and engine-driven rear road wheels  11 B on rear tandem rear axles, which collectively form a road-operable truck vehicle. 
         [0017]    For adapting the cab-chassis to a waste collection vocation, a waste collection body  12  is mounted on chassis  11  rearward of cab  33 . 
         [0018]    Body  12  comprises an understructure  13  and various panels, such as panels  14 , cooperatively defining a waste collection space  16 , a hopper  17  having a hopper opening  18  in the top of body  12  toward the front of truck vehicle  10  and a discharge opening  100  at the rear of truck vehicle  10 . Body  12  comprises an upright rectangular rear frame  101  (see  FIG. 2 ) which surrounds discharge opening  100 . 
         [0019]    A tailgate  20  is pivotally mounted on rear frame  101  to swing about a horizontal axis  41  at the top of rear frame  101 . A motive means such as hydraulic cylinder assemblies (not visible in the drawing views) are connected between tailgate  20  and rear frame  101 . The motive means operates to swing tailgate  20  from a closed position ( FIGS. 1 ,  2 , and  3 ) to open discharge opening  100 , allowing collected waste to be pushed out of waste collection space  16  through discharge opening  100 . When waste collection space  16  has been emptied, the motive means operates to swing tailgate  20  downwardly to re-close discharge opening  100 . 
         [0020]    Body  12  further comprises a front loading container pickup mechanism  21  having a left pickup arm  22  and a right pickup arm  23  whose lower ends are pivotally mounted on body  12  for swinging about an axis  24 . 
         [0021]    A motive means such as a hydraulic cylinder  26  is connected between each arm  22 ,  23  and body  12  for pivoting pickup arms  22 ,  23  counterclockwise about axis  24  from a rest position shown in  FIGS. 1 and 2 . Container pickup mechanism  21  comprises a pickup fork having tines  27 ,  28 , pivotally mounted on the upper ends of pickup arms  22 ,  23  respectively. A left hydraulic cylinder  29  is connected between tine  27  and left pickup arm  22 . A right hydraulic cylinder  30  is connected between tine  28  and right pickup arm  23 . 
         [0022]    Hydraulic cylinders  29 ,  30  are operable to pivot the respective tines  27 ,  28  between a rest position shown in  FIGS. 1 and 2  and an extended position for engagement of a waste container (not shown) whose contents are to be emptied into body  12 . Coordinated pivoting of pickup arms  22 ,  23  and tines  27 ,  28  from their respective rest positions enables tines  27 ,  28  to engage an upright waste container which is in front of truck vehicle  10 , and then pickup arms  22 ,  23  to lift the waste container and swing it over cab  33  while turning the waste container generally upside down to allow its contents to fall out of the waste container and through hopper opening  18  into hopper  17 . Hydraulic cylinders  29 ,  30  are then operated to return the empty waste container to upright position in front of the vehicle after which tines  27 ,  28  are disengaged from the waste container, and they and pickup arms  22 ,  23  are returned to their rest positions. 
         [0023]    Body  12  also comprises a packer mechanism (not shown) which can be extended in a direction toward the rear of truck vehicle  10  to push waste from hopper  17  into waste collection space  16 . When waste collection space  16  has been fully packed, truck vehicle  10  can be driven to a suitable dump site where waste collection space  16  is emptied. 
         [0024]    Emptying of waste collection space  16  is accomplished by swinging tailgate  20  open and operating the packer mechanism to push waste out of waste collection space  16  through discharge opening  100 . After the waste has been discharged, tailgate  20  is swung closed and the packer mechanism is retracted. 
         [0025]    Hopper opening  18  can be opened and closed by a hopper door  35  which slides in tracks between an open position shown in  FIGS. 1 and 2  and a closed position covering hopper opening  18 . Motive means such as a hydraulic cylinder assembly  37  is operable to move door  35  between its open and closed positions. 
         [0026]    Tailgate  20  comprises a generally rectangular tailgate frame  68  that, when tailgate  20  is closed, fits to rear frame  101  to close discharge opening  100 . The interior of the tailgate cavity that is open to the rear of waste collection space  16  when tailgate  20  is closed has a lower cavity portion defined by left and right lower side plates  69  extending rearward from their attachment to lower portions of vertical sides of tailgate frame  68  and by a curved bottom plate  67  extending laterally of body  12  between side plates  69 . An upper cavity portion interior of the tailgate cavity that is open to the rear of waste collection space  16  when tailgate  20  is closed is defined by portions of upright side panels  74 ,  84  and cross panels  81 ,  82 ,  83  ( FIG. 4 ) which extend between side panels  74 ,  84 . 
         [0027]    A horizontal support frame  73  extends horizontally rearward from the vertical sides of tailgate frame  68  at a common boundary of the upper and lower cavity portions of the tailgate cavity. Support frame  73  comprises side members  73 A,  73 B ( FIG. 4 ) which extend rearward from attachment to respective vertical sides of tailgate frame  68  and an end member  73 C which extends laterally between rear ends of side members  73 A,  73 B. Side panels  74 ,  84  attach along their horizontal bottom margins to side members  73 A,  73 B respectively and along their front vertical margins to respective vertical sides of tailgate frame  68 . Side plates  69  attach along their horizontal top margins to side members  73 A,  73 B respectively. The top margin of bottom plate  67  attaches to end member  73 C. 
         [0028]    The engine of truck vehicle  10  has an alternative fuel system, one example of which is a compressed natural gas (CNG) fuel system. On-board storage  50  of CNG for use by the engine comprises at least one fuel storage cylinder mounted on a fuel pod frame  54  ( FIG. 4 ) to form a CNG fuel pod  51 . The alternative fuel system comprises various components, including connection lines, relief valves, gauges, regulators and other elements, that provide for delivery of CNG from the fuel storage cylinder or cylinders to the engine and for monitoring operation and status of the alternative fuel system. 
         [0029]      FIG. 4  shows one example of a fuel pod  51  comprising a fuel pod frame  54  holding five fuel storage cylinders  55 ,  56 ,  57 ,  58 ,  59  which store CNG. The space between side panels  74 ,  84  on the exterior of cross panels  81 ,  82 ,  83  forms a fuel pod compartment  88  for fuel pod  51 . 
         [0030]    Fuel pod frame  54  comprises a base disposed against an exterior surface of cross panel  83  which inclines downwardly away from the front of truck vehicle  10 . The base of fuel pod frame  54  is attached to cross panel  83 . Fuel pod frame  54  also comprises side member assemblies  54 A,  54 B at laterally opposite sides of the base, and it is between those side member assemblies  54 A,  54 B that fuel storage cylinders  55 ,  56 ,  57 ,  58 ,  59  are arranged in two rows with the long dimensions of the cylinders running laterally between side member assemblies  54 A,  54 B. 
         [0031]    Fuel storage cylinders  55 ,  57 ,  59  are arranged in succession side-by-side in an underlying row, and fuel storage cylinders  56 ,  58  are arranged side-by-side in an overlying row where each nests between a pair of fuel storage cylinders in the underlying row. 
         [0032]    Fuel storage cylinders  55 ,  56 ,  57 ,  58 ,  59  are fit to, and removably secured in, fuel pod frame  54  via side member assemblies  54 A,  54 B. Various means of mounting fuel storage cylinders on a frame are known. The drawings show one example where opposite ends of each fuel storage cylinder have reduced diameter necks  120  such as the one seen in  FIG. 5  which is an enlarged view in circle  5  in  FIG. 4 . Each neck  120  is captured by a respective yoke  122  also seen in  FIG. 5 . Each yoke  122  comprises an underlying part  122 A mounted on a respective side member assembly  54 A,  54 B and an overlying part  122 B. Underlying part  122 A comprises a semi-circular cradle in which a neck  120  is received. Overlying part  122 B comprises a semi-circular recess which fits over neck  120 . Fasteners  124  fasten overlying part  122 B to underlying part  122 A to each side of neck  120 . 
         [0033]    Each fuel storage cylinder has a port at one lengthwise end. A respective shutoff valve  63 , an example of which is seen in  FIG. 5 , comprises a first valve port fit to a respective cylinder port in a sealed manner. The particular shut-off valve  63  shown also comprises a second valve port  126 , a third valve port  128 , and a fourth valve port  130 . 
         [0034]    Shut-off valves  63  are is disposed on the interior of side panel  84 , each being proximate a respective access hole  132  in side panel  84  for providing hand access for manually turning a valve handle  134  of the respective shut-off valve  63  to open and close the respective fuel storage cylinder. When open, a shut-off valve  63  allows CNG to flow into the respective fuel storage cylinder for re-filling and CNG to flow out of the respective fuel storage cylinder for operating the engine. Fuel lines (shown schematically in  FIG. 6 ) connect to shut-off valves  63  for conveying CNG between the fuel storage cylinders and a fuel management module  136  mounted on body  12 . Fuel management module  136  includes appropriate elements for controlling delivery of CNG from the fuel storage cylinders to the engine in proper quantity and pressure and controlling delivery of CNG to the fuel storage cylinders when they are being re-filled. The fuel lines are also disposed on the interior of side panel  84 , but exit fuel pod compartment  88  before reaching fuel management module  136   
         [0035]      FIG. 6  shows that the five fuel storage cylinders are connected in a chain so that when any shut-off valve  63  is open, the respective fuel storage cylinder is on-line to the chain and capable of delivering CNG for operating the engine or being re-filled with CNG during re-fueling. The last shut-off valve in the chain has its port  128  capped. Each fourth valve port  130  is a vent port which is normally closed, but opens to vent CNG when in-cylinder pressure exceeds a pressure limit. 
         [0036]    Not shown in  FIGS. 1 ,  2 , and  3 , but shown in  FIG. 4 , are covers  138  each of which is associated with a respective access hole  132  on the exterior of side panel  84 . Covers  138  are gravity-biased to close the respective access hole  132 , but can swung upward by hand to uncover the respective access hole  132  and held there to allow hand access to the respective valve handle  134 . 
         [0037]    Three cover plates  91 ,  92 ,  93  are attached to flanges  75  of right and left side plates  69  to enclose fuel pod  51  within compartment  88 , with the bottom margin of cover plate  93  attaching to a flange which is parallel with end member  73 C. 
         [0038]    Placement of fuel pod  51  rearward of the tandem rear axles rather than at a location more toward the front of truck vehicle  10  moves the center of gravity of truck vehicle  10  more toward the rear, more favorably counterbalancing weight of front loading container pickup mechanism  21 . That placement also leaves more space on chassis  11  for mounting other components. The drawings show the entire fuel pod rearward of the tandem rear axles. 
         [0039]    Alternative embodiments are contemplated such as one (not illustrated) in which fuel pod  51  is configured to hold six fuel storage cylinders in an arrangement which positions a sixth fuel storage cylinder nested atop and between fuel storage cylinders  56  and  58 . Pod frame  54  is modified to hold the sixth fuel storage cylinder, with other elements forming compartment  88  being re-sized as appropriate. If a customer orders a new vehicle with a five cylinder fuel pod, but finds through use that more fuel storage capacity is needed, parts can be added to fuel pod frame  54  on side member assemblies  54 A,  54 B between fuel storage cylinders  56  and  58  to support a pair of additional yokes  122  for mounting the sixth fuel storage cylinder. Fuel and vent lines are connected to the shut-off valve of the added fuel cylinder to place it in the chain. One or more of cover plates  91 ,  92 ,  93  bounding fuel pod compartment  88  may be modified and/or replaced. 
         [0040]    While the disclosed embodiment has been described in the context of a Class 8 frontloading waste collection truck vehicle, embodiments can be designed for other vocational uses in other sized truck vehicles. By integrating a fuel pod with structure of a vocational body as shown, existing body structure may be sufficient to support the weight of a fuel pod. The fuel pod is more sheltered than at other locations and frees up space elsewhere in the vocational body and the vehicle chassis. The fuel pod doesn&#39;t contribute to vehicle height, or reduce vehicle road clearance, and it is out of the way of areas which are likely to be impacted by collisions.