Abstract:
A revised location for the fuel system and fuel tanks to improve crashworthiness and reduce the occurrence of tank failure, fuel spillage, fire and/or explosion while still providing a sufficient range for the vehicle. The fuel tank system includes at least one fuel tank and a support structure. The at least one fuel tank is provided proximate frame rail members of the truck. At least a portion of the at least one fuel tank extends between an extension of a vertical axis of each of the frame rail members. The support structure protects the at least one fuel tank during an event, such as, but not limited to a collision, crash or accident. The support structure includes at least one mounting member which attaches the at least one fuel tank to the frame rail members, rails which extend about the at least one fuel tank, and at least one bottom plate.

Description:
FIELD OF THE INVENTION 
     The present invention is directed to a fuel system and fuel tanks for heavy duty trucks, and more particularly to protecting the fuel tanks and fuel system during a crash. 
     BACKGROUND OF THE INVENTION 
     It is generally known that in configuring a motor vehicle with a fuel tank, it is important to prevent the fuel tank from damage and spillage during the crash. There are several strategies that have been employed in automotive design to meet those desires and requirements. 
     Those strategies include, but are not limited to, placing the fuel tank away from the perimeter of the vehicle, ensuring crush space is provided to absorb crash energy before the fuel tank is affected, constructing the fuel tank of materials that are not easily cut or torn, applying shields in areas of the fuel tank that may be vulnerable, routing all supply lines in protected areas, and providing the filler with a check valve to prevent leakage. 
     Automobiles and light trucks must pass standards for fuel tank leakage in all mandated crash tests that range from frontal impacts, to side impacts to rear impacts. However, heavy trucks other than school buses have no federal requirements for crashworthiness of the fuel system. 
     Currently most manufacturers of heavy trucks mount thin wall aluminum or steel tanks to the outside of the frame rails for carrying fuel. Due to the location and construction of the fuel tanks in heavy trucks, the tank is exposed to crushing during various crash events, resulting in an increased possibility of fuel spillage, fire and explosion. These risks are a known hazard in fuel storage areas or vehicles, and are considered significant if there is an accident causing an object, such as, but not limited to, debris from an accident or the guide rail, to penetrate the fuel tank. Rupturing of fuel tanks is believed to be a common reason for fires or explosions. 
     It would be desirable to provide a truck fuel tank system which overcomes the problems stated above. It would also be desirable to provide for revised placement and protection for the fuel tanks and fuel system, thereby improving crashworthiness and reducing the occurrence of tank failure, fuel spillage, fire and/or explosion. 
     SUMMARY OF THE INVENTION 
     The invention provides a revised location for the fuel system and fuel tanks to improve crashworthiness and reduce the occurrence of tank failure, fuel spillage, fire and/or explosion while still providing a sufficient range for the vehicle. The fuel tanks are protected from damage from the side, bottom and between the tanks. 
     In one embodiment, a fuel tank system for use with a tractor of a tractor trailer truck or other heavy truck is provided. The fuel tank system includes at least one fuel tank and a support structure. The at least one fuel tank is provided proximate frame rail members of the tractor. At least a portion of the at least one fuel tank extends between an extension of a vertical axis of each of the frame rail members. The support structure protects the at least one fuel tank during an event, such as, but not limited to a collision, crash or accident. 
     In one embodiment, a fuel tank system for use with a heavy truck is provided. The fuel tank system includes at least one fuel tank and a support structure. The at least one fuel tank is provided proximate frame rail members of the truck. At least a portion of the at least one fuel tank extends between an extension of a vertical axis of each of the frame rail members. The support structure protects the at least one fuel tank during an event, such as, but not limited to a collision, crash or accident. The support structure includes at least one mounting member which attaches the at least one fuel tank to the frame rail members, at least one rail which extends about the at least one fuel tank, and at least one bottom plate. 
     In one embodiment, a fuel tank system for use with a heavy truck is provided. The fuel tank system includes a fuel tank and a support structure. The fuel tank is positioned proximate an underside of the heavy truck between a first side of the heavy truck and a second side of the heavy truck. The support structure, which protects the fuel tank during an event, such as, but not limited to a collision, crash or accident, includes at least one mounting member which attaches the fuel tank to the underside of the heavy truck, at least one rail which extends about the fuel tank, and at least one bottom plate. 
     In one embodiment, the fuel tanks are provided beneath the frame rail members of the vehicle. A support structure may be provided for support on each side of the vehicle which also acts as a guard for the tank. A bottom plate may also be provided to protect the tanks from intrusion from below and protect the tanks in the event of a front axle attachment failure and the resulting impact and ground contact. Additionally, a guard section may be positioned between the tanks to provide protection for the tanks in the event of a drive shaft or drive line failure. 
     The use of the support structure provides both impact and tearing protection for the tank. This support structure also allows mounting of other components such as exhaust, air tanks, and emission control systems to the outside of the structure. These mounted components will further act as energy absorbing members, further protecting the tank. The support structure also allows mounting of additional energy absorbing devices or structures as needed. 
     The bottom plate will protect the bottom of the tank from crush or puncture and serve as a skid plate if ground contact is made. The front edge of the bottom plate may be turned up to allow for protection to the front side of the tank or tanks. The bottom plate also provides a location for mounting and location hardware and brackets for the tank. 
     The support structure may be mounted to tank locating brackets attached to the bottom plate. This may be formed in a U-section with wings which will serve as tank retention brackets. 
     Additional protection may be provided by energy absorbing capabilities of accessories mounted outside of the tanks and energy absorbing brackets. 
     In one embodiment, the fuel lines are routed within the structure and the frame rails. The tanks would be filled from a tube routed out the rear side of the tanks and structure with an integrated check system in the tank to prevent in the event of failure of this hose. 
     Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of components of an illustrative embodiment of a fuel system according to the present invention. 
         FIG. 2  is a top view of the fuel system of  FIG. 1 . 
         FIG. 3  is a front view of the fuel system of  FIG. 1 . 
         FIG. 4  is a side view of the fuel system of  FIG. 1 . 
         FIG. 5  is a front perspective view of components of an alternate illustrative embodiment of a fuel system according to the present invention, with one of the vehicle frame rail members removed. 
         FIG. 6  is a perspective view of the components of the alternate illustrative embodiment of a fuel system shown in  FIG. 5  with the fuel tanks removed and both of the vehicle frame rail members shown. 
         FIG. 7  is a top view of the fuel system of  FIG. 5 , with both of the vehicle frame rail members shown. 
         FIG. 8  is a back perspective view of the fuel system of  FIG. 5 , with both of the vehicle frame rail members shown. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The description of illustrative embodiments according to principles of the present invention is intended to be read in connection with the accompanying drawings, which are to be considered part of the entire written description. In the description of embodiments of the invention disclosed herein, any reference to direction or orientation is merely intended for convenience of description and is not intended in any way to limit the scope of the present invention. Relative terms such as “lower,” “upper,” “horizontal,” “vertical,” “above,” “below,” “up,” “down,” “top” and “bottom” as well as derivative thereof (e.g., “horizontally,” “downwardly,” “upwardly,” etc.) should be construed to refer to the orientation as then described or as shown in the drawing under discussion. These relative terms are for convenience of description only and do not require that the apparatus be constructed or operated in a particular orientation unless explicitly indicated as such. Terms such as “attached,” “affixed,” “connected,” “coupled,” “interconnected,” and similar refer to a relationship wherein structures are secured or attached to one another either directly or indirectly through intervening structures, as well as both movable or rigid attachments or relationships, unless expressly described otherwise. Moreover, the features and benefits of the invention are illustrated by reference to the preferred embodiments. Accordingly, the invention expressly should not be limited to such preferred embodiments illustrating some possible non-limiting combination of features that may exist alone or in other combinations of features; the scope of the invention being defined by the claims appended hereto. 
     Referring now to the drawings wherein like reference characters refer to like and corresponding parts throughout the several views, there is shown in  FIGS. 1 through 4 , two fuel tanks  10  which are part of a fuel system  12  for a tractor of a tractor trailer truck or other heavy trucks or similar type vehicles. While two fuel tanks are shown, at least one fuel tank or other numbers of fuel tanks may be used without departing from the scope of the invention. 
     Each fuel tank  10  can be made in one piece, as shown in the drawings. Alternatively, the fuel tanks can be made using conventional methods, such as, but not limited to having a bottom pan member and a top pan member joined in any conventional manner, such as by a series of continuous welds which fasten together flanges of the bottom pan member and the top pan member. The material used to form the fuel tanks can be any material which will not degrade or fail when exposed to the fuel (i.e. diesel) which is stored in the fuel tanks  10 , such as, but not limited to, polyethylene. 
     An inlet pipe or tube (not shown) is secured to the fuel tank  10 , for example through a top wall  18  of the tank  10 . The inlet tube may be secured to the fuel tank  10  in any known manner. The inlet tube is for the purpose of introducing diesel or other desired fuel into the respective tank  10 . The inlet tube may be secured to the fuel tank  10  at various locations, including, but not limited to, near the rearward end of the tank  10 . A gasoline feed tube or pipe (not shown) extends from the fuel tank  10 , for example through a bottom wall  22 , for the purpose of feeding the fuel to the engine of the vehicle. The feed tube or pipe may be located at various locations, including, but not limited to, near the forward end of the tank  10 . 
     As best shown in  FIGS. 1 and 3 , the tanks  10  are adapted to be horizontally attached to the underside of the truck or vehicle so that the top walls  18  and the bottom walls  22  of the tanks are essentially parallel to the plane of the longitudinal axis of frame rail members  30  of the truck or motor vehicle and essentially parallel to the longitudinal axis of the drive shaft or drive line (not shown) of the vehicle. It should be understood that the cross section and overall shape of the fuel tanks  10  can be of any desired modification based on the space available for the tanks  10  and the desired capacity of the tank  10 . In the embodiment shown in  FIGS. 1 through 4 , sloped walls  24 ,  26  (as best shown in  FIG. 3 ) extend from top walls  18 . Sloped walls  24  are dimensioned to cooperate with mounting members  40 , as will be more fully described. Slope walls  26  are configured to allow the fuel tanks  10  to be installed about the drive shaft. This configuration of the sloped surfaces  24 ,  26  causes the fuel tanks  10  to be pushed downward, away from the drive shaft and away from the frame rail members  30 , during an event, such as, but not limited to a collision, crash or accident. As any force is applied to the fuel tanks  10  during such an event, the sloped surfaces  24 ,  26  cause the applied forces to exhibit a partial downward force on the fuel tanks  10 , causing the fuel tanks  10  to be moved away from the drive shaft. 
     As best shown in  FIG. 1 , the fuel system  12  includes the fuel tanks  10 , mounting members  40 , at least one rail  50  and at least one bottom plate  60 . The mounting members  40  have an S-shaped configuration with a first end section  42 , a middle section  44  and a second end section  46 . The first end section  42  of each mounting member  40  is mounted to a respective frame member  30  of the vehicle using known mounting methods, such as, but not limited to bolting the first end section  42  to the frame  30 . The second end section  46  of each mounting member  40  is mounted to a respective rail  50  using known mounting methods, such as, but not limited to bolting the second end section  46  to the rail  50 . The second end section  46  of each mounting member  40  may also be mounted to the bottom plate  60  using known mounting methods, such as, but not limited to bolting the second end section  46  to the bottom plate  60 . Alternatively, or additionally, the bottom plate  60  may be mounted to the rails  50  using known mounting methods, such as, but not limited to bolting the rails  50  to the bottom plate  60 . 
     The mounting members  40  may have a nonlinear cross-section to provide additional strength to the mounting members  40 , thereby enhancing the ability of the mounting members  40  to support additional weight and to provide additional crush resistance for the fuel tanks  10  The nonlinear configuration of the mounting members  40  allows for forces applied thereto to be better dissipated over the entire surface of the mounting members  40 , thereby preventing lateral forces from being transferred directly to the fuel tanks  10  during an event, such as, but not limited to a collision, crash or accident. The mounting members  40  may be made from any material having the strength characteristics desired, including, but not limited to, steel and cross-linked polyethylene. 
     As best shown in  FIG. 3 , the middle section  44  is dimensioned to have a downward tilt, away from the frame members  30 . In one embodiment, the angled of the downward tilt is approximately equal to the slope of the sloped wall  24 . Consequently, as a lateral force is applied to the mounting members  40 , the middle section  44  cooperates with the surface  24  causing the lateral force to be partially translated to a downward force, causing the fuel tanks  10  to be moved downward away from the frame members  30  and the drive shaft. In so doing, the fuel tank  10  is moved away from the drive shaft during an event, such as, but not limited to a collision, crash or accident, thereby preventing the fuel tanks  10  from being punctured by the drive shaft. 
     The spacing of the mounting members  40  along the fuel tanks  10  can be varied depending upon the capacity of the fuel tanks  10  and the amount of protection required to prevent puncture of the fuel tanks  10  during or as a result of an such an event. Alternatively, the mounting member  40  may be a solid member to provide enhanced protection. 
     As shown in  FIG. 3 , rails  50  may have a nonlinear cross-section to provide additional strength to the rails  50 , thereby enhancing the ability of the rails  50  to provide additional integrity to the system  12  and to provide additional crush resistance for the fuel tanks  10 . The nonlinear configuration of the rails  50  allows for forces applied thereto to be better dissipated over the entire surface of the rails  50 , thereby preventing lateral forces from being transferred to the fuel tanks  10  during an event, such as, but not limited to a collision, crash or accident. The rails  50  may be made from any material having the strength characteristics desired, including, but not limited to, steel and cross-linked polyethylene. 
     In the illustrative embodiment, the bottom plate  60  extends below the entire width and length of the fuel tanks  10 . As shown in  FIG. 3 , the bottom plate  60  may have a nonlinear cross-section to provide additional strengthening ribs  66  to the bottom plate  60 , thereby enhancing the ability of the bottom plate  60  to provide additional integrity to the system  12  and to provide additional crush resistance for the fuel tanks  10 . The nonlinear configuration of the bottom plate  60  allows for forces applied thereto to be better dissipated over the entire surface of the bottom plate  60 , thereby preventing damaging forces from being transferred to the fuel tanks  10  during such an event. The bottom plate  60  may be made from any material having the strength characteristics desired, including, but not limited to, steel and cross-linked polyethylene. The strengthening ribs  66  may be space periodically along the bottom plate  60  or may be more uniformly distributed, depending upon the material used for the bottom plate  60  and the strength characteristics desired. 
     The bottom plate  60  protects the fuel tanks  10  from intrusion from below and protects the fuel tanks  10  in the event of a front axle attachment failure and the resulting impact and ground contact. The bottom plate  60  protects the bottom of the fuel tanks  10  from being crushed or punctured and serves as a skid plate if ground contact is made. A front edge  62  ( FIG. 4 ) of the bottom plate  60  may be turned up to allow for protection to the front side of the fuel tanks  10 . The bottom plate  60  also provides a location for conventional mounting and location hardware and brackets to mount the fuel tanks  10  to the bottom plate  60 . The mounting members  40  may also be mounted to the tank locating brackets attached to the bottom plate  60 . In one embodiment, the tank locating bracket may be formed in a U-section with wings which serve as tank retention brackets. 
     A guard  70  ( FIG. 1 ) may be positioned between the fuel tanks  10  to provide protection for the tanks  10  in the event of a drive shaft failure. The guard may be made from any material having the strength characteristics desired, including, but not limited to, steel and cross-linked polyethylene. 
     An alternate illustrative embodiment is shown in  FIGS. 5 through 9 . In this embodiment, a single fuel tank  110  is shown. While one fuel tank is shown in the system  112 , other numbers of fuel tanks may be used without departing from the scope of the invention. As one illustrative option, the fuel tanks may be modular, allowing the appropriate number of tanks to be used to accommodate the desired fuel capacity. The material used to form the fuel tanks can be any material which will not degrade or fail when exposed to the fuel (i.e. diesel) which is stored in the fuel tank  110 , such as, but not limited to, polyethylene. 
     An inlet pipe or tube  120  is secured to the fuel tank  10 , for example through a side wall  119  of the tank  110 . The inlet tube may be secured to the fuel tank  110  in any known manner. The inlet tube is for the purpose of introducing diesel or other desired fuel into the respective tank  10 . The inlet tube may be secured to the fuel tank  10  at various locations, including, but not limited to, near the rearward end of the tank  10 . As shown in  FIG. 6 , openings may be provided through the rail frame members  130  and the mounting member  140  to allow the inlet pipe  120  to access the tank  110 . A gasoline feed tube or pipe (not shown) extends from the fuel tank  10 , for example through a bottom wall  122 , for the purpose of feeding the fuel to the engine of the vehicle. The feed tube or pipe may be located at various locations, including, but not limited to, near the forward end of the tank  110 . 
     As best shown in  FIGS. 5 and 8 , the tanks  110  are adapted to be horizontally attached to the underside of the truck or vehicle so that portions  121  of the tanks  110  are positioned between the frame rail members  130  and cross supports  131  of the truck or motor vehicle. A channel  133  is provided to accommodate the drive shaft or drive line (not shown) of the vehicle. It should be understood that the cross section and overall shape of the fuel tank  110  can be of any desired modification based on the space available for the tank  110  and the desired capacity of the tank  10 . In the embodiment shown, the rail frame members  130  are notched at  141  (as shown in  FIG. 6 ) to allow for the tank  110  to be positioned between the rail frame members  130 . When mounted to the rail frame members  130 , the combination of the mounting members  140 , rails  150  and bottom plate  160  provide additional strength to the rail frame members  130  to compensate for any weakness to the rail frame members  130  caused by the notches  141 . 
     The fuel system  112  includes the fuel tank  110 , mounting members  140 , at least one rail  150  and at least one bottom plate  160 . As best shown in  FIG. 8 , the mounting members  140  have an S-shaped configuration with a first end section  142 , a middle section  144  and a second end section  146 . The first end section  142  of each mounting member  140  is mounted to a respective frame member  130  of the vehicle using known mounting methods, such as, but not limited to bolting the first end section  142  to the frame  130 . The second end section  146  of each mounting member  140  is mounted to the bottom plate  160  using known mounting methods, such as, but not limited to bolting the second end section  146  to the bottom plate  160 . The second end section  146  of each mounting member  140  may also be mounted to a respective rail  150  using known mounting methods, such as, but not limited to bolting the second end section  146  to the rail  150 . Alternatively, or additionally, the bottom plate  160  may be mounted to the rails  150  using known mounting methods, such as, but not limited to bolting the rails  150  to the bottom plate  160 . 
     As best shown in  FIG. 8 , the middle section  44  is dimensioned to have a flange  135  which extends away from the frame members  130 . Extending from the flange  135  to the bottom plate  160  are one or more support members or struts  137 . The support members or struts  137  provide additional support to the system  112  and maintain the bottom plate  160  in position relative to the rail frame members  130  during normal operation. However, in case of an event, such as, but not limited to a collision, crash or accident, the support members or struts  137  are designed to fail, causing the bottom plate  160  and the fuel tank  110  to be fall downward away from the frame members  130  and the drive shaft. In so doing, the fuel tank  110  is moved away from the drive shaft during such an event, thereby preventing the fuel tank  110  from being punctured by the drive shaft. 
     In the embodiment shown, each mounting member  140  is one piece which extends along the entire side of the fuel tank  110 . However, the configuration of the mounting members  140  can be varied depending upon the capacity of the fuel tank  110  and the amount of protection required to prevent puncture of the fuel tank  110  during or as a result of such an event. For example, the mounting members  40  may be individual members rather than a solid member (similar to that shown in  FIGS. 1 through 4 ). 
     As shown in  FIGS. 5, 6 and 8 , rails  150  may have a nonlinear cross-section to provide additional strength to the rails  150 , thereby enhancing the ability of the rails  150  to provide additional integrity to the system  112  and to provide additional crush resistance for the fuel tank  110 . The nonlinear configuration of the rails  150  allows for forces applied thereto to be better dissipated over the entire surface of the rails  150 , thereby preventing lateral forces from being transferred to the fuel tanks  110  during such an event. The rails  150  may be made from any material having the strength characteristics desired, including, but not limited to, steel and cross-linked polyethylene. 
     In the illustrative embodiment, the bottom plate  160  extends below the entire width and length of the fuel tank  110 . As shown in  FIG. 6 , the bottom plate  160  may have a nonlinear cross-section to provide additional strengthening ribs  166  to the bottom plate  160 , thereby enhancing the ability of the bottom plate  160  to provide additional integrity to the system  112  and to provide additional crush resistance for the fuel tank  110 . The nonlinear configuration of the bottom plate  160  allows for forces applied thereto to be better dissipated over the entire surface of the bottom plate  160 , thereby preventing damaging forces from being transferred to the fuel tank  110  during an event, such as, but not limited to a collision, crash or accident. The bottom plate  160  may be made from any material having the strength characteristics desired, including, but not limited to, steel and cross-linked polyethylene. The strengthening ribs  166  may be space periodically along the bottom plate  160  or may be more uniformly distributed, depending upon the material used for the bottom plate  160  and the strength characteristics desired. 
     The bottom plate  160  protects the fuel tank  110  from intrusion from below and protects the fuel tank  110  in the event of a front axle attachment failure and the resulting impact and ground contact. The bottom plate  160  protects the bottom of the fuel tank  110  from being crushed or punctured and serves as a skid plate if ground contact is made. One or more front plates  163  ( FIG. 3 ) may be attached or integral to the bottom plate  160  and or the mounting members  140  and or the rails  150  may be provided to allow for additional protection to the front side of the fuel tank  110 . The bottom plate  60  also provides a location for conventional mounting and location hardware and brackets to mount the fuel tank  110  to the bottom plate  160 . The mounting members  140  may also be mounted to the tank locating brackets attached to the bottom plate  160 . In one embodiment, the tank locating bracket may be formed in a U-section with wings which serve as tank retention brackets. 
     A guard (not shown, but similar to that shown in  FIGS. 1 through 4 ) may be positioned in the channel  133  to provide protection for the tank  110  in the event of a drive shaft failure. The guard may be made from any material having the strength characteristics desired, including, but not limited to, steel and cross-linked polyethylene. 
     As shown in the illustrative embodiments of  FIGS. 1-8 , the frame members  30 , mounting members  40 , rails  50  and the bottom plate  60  form a protective area, cage or support area which provides a crush-free zone for the fuel tank(s)  10 . The support structure may be provided for support on each side of the vehicle which also acts as a guard for the fuel tank. The use of the support structure provides both impact and tearing protection for the fuel tank(s)  10 . This support structure also allows mounting of other components such as exhaust, air tanks, and emission control systems to the outside of the structure. These mounted components will further act as energy absorbing members, further protecting the fuel tanks. The support structure also allows mounting of additional energy absorbing devices or structures as needed. 
     While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the spirit and scope of the invention of the invention as defined in the accompanying claims. In particular, it will be clear to those skilled in the art that the present invention may be embodied in other specific forms, structures, arrangements, proportions, sizes, and with other elements, materials, and components, without departing from the spirit or essential characteristics thereof. One skilled in the art will appreciate that the invention may be used with many modifications of structure, arrangement, proportions, sizes, materials, and components and otherwise, used in the practice of the invention, which are particularly adapted to specific environments and operative requirements without departing from the principles of the present invention. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being defined by the appended claims, and not limited to the foregoing description or embodiments.