Abstract:
A motorcycle frame having first, second, and third frame sections. The first frame section is sized and configured to receive and secure a motorcycle engine. The second frame section is located rearwardly from the first frame section, and is sized and configured to receive and secure a motorcycle transmission and support a motorcycle driver seat. The third frame section is located rearwardly from the second frame section, and is sized and configured to support a motorcycle passenger seat forward of a rear tire of the motorcycle.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/744,428, filed Apr. 7, 2006, the contents of which are incorporated herein by reference. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention generally relates to motorcycles. More particularly, this invention relates to a motorcycle frame that enables a passenger seat to be accommodated in front of the rear wheel of a motorcycle, rather than above the rear wheel. 
         [0003]      FIG. 1  schematically represents a conventional frame  10  for a two-wheeled motorcycle (shown in phantom). The frame  10  is represented as having a front section  12  where an engine (not shown) would be ordinarily accommodated, and a rear section  14  immediately behind the front section  12  where a transmission (not shown) is ordinarily accommodated and above which an operator seat (not shown) is mounted. A pair of rear wheel suspension forks  16  is mounted rearward from the rear section  14  and a passenger seat (not shown) is mounted over the rear wheel  18  of the motorcycle. As evident from  FIG. 1 , in the typical riding position of such a conventional two-wheeled motorcycle, the passenger sits with higher elevation than the operator due to the passenger seat location above the rear wheel  18 . 
         [0004]    There are a number of disadvantages associated with conventional motorcycle frame configurations of the type shown in  FIG. 1 . When the passenger is located above the rear wheel  18 —that is, with his or her torso extending above the rear wheel  18 —the combined center of gravity of the motorcycle and rider (including the passenger) is relatively high. This reduces maneuverability of the motorcycle and increases the tendency to tip over. Furthermore, with the torso of the passenger fully exposed above the motorcycle, wind drag is increased reducing fuel economy. Still further, the passenger is largely exposed so that in the event of an accident, there is a greater tendency for a serious injury. 
         [0005]    Accordingly, there is need for motorcycle frames capable of increasing the safety and fuel economy of motorcycles while also enhancing their operational characteristics and comfort. 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The present invention provides a motorcycle frame capable of increasing the safety and fuel economy of a motorcycle while also enhancing its operational characteristics and comfort. 
         [0007]    The motorcycle frame generally includes first, second, and third frame sections. The first frame section is sized and configured to receive and secure a motorcycle engine. The second frame section is located rearwardly from the first frame section, and is sized and configured to receive and secure a motorcycle transmission and support a motorcycle driver seat. The third frame section is located rearwardly from the second frame section, and is sized and configured to support a motorcycle passenger seat forward of a rear tire of the motorcycle. 
         [0008]    In view of the above, it can be seen that the motorcycle frame of this invention is capable of increasing the safety and fuel economy of a motorcycle while also enhancing its operational characteristics and comfort by locating the passenger seat in front of the rear wheel, rather than above the rear wheel. By accommodating the passenger in front of the rear wheel, additional space is created under the passenger seat that may have a broad range of uses. 
         [0009]    Other objects and advantages of this invention will be better appreciated from the following detailed description. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  schematically represents a side view of a motorcycle frame in accordance with the prior art. 
           [0011]      FIGS. 2 and 3  schematically represent side and top views of a motorcycle frame in accordance with an embodiment of this invention. 
           [0012]      FIG. 4  schematically represents an isolated top view of a frame extension of the motorcycle frame of  FIGS. 2 and 3 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0013]      FIGS. 2 and 3  schematically represent a motorcycle frame  20  configured to increase the safety and fuel economy of a motorcycle (shown in phantom), while also enhancing the operational characteristics and comfort of the motorcycle. The frame  20  achieves this preferred aspect of the invention by locating the passenger seat in front of the rear wheel  18  as seen in  FIG. 2 , rather than above the rear wheel  18  as seen in  FIG. 1 . By accommodating the passenger in front of the rear wheel  18 , additional space is created under the passenger seat which may have a broad range of uses, as represented in  FIGS. 3 and 4 . 
         [0014]    To accomplish the above, the motorcycle frame  20  is extended by the inclusion of a frame section  30 , which is in addition to a front frame section  22  where the motorcycle engine (not shown) is ordinarily accommodated and a frame section  24  immediately behind the front frame section  22  and where the motorcycle transmission (not shown) is ordinarily accommodated. The additional frame section  30  is located within the frame  20  between the transmission frame section  24  and the rear wheel suspension forks  16 , the latter of which may be pivotally attached to the frame section  30 . As evident from  FIG. 2 , the frame section  30  is able to accommodate a passenger seat, which may be a discrete seat or part of the driver seat on the transmission frame section  24 . As evident from  FIG. 2 , the frame section  30  locates the passenger seat in front of the rear wheel  18 , instead of above the rear wheel  18  as done conventionally (e.g.,  FIG. 1 ).  FIG. 4 , which schematically represents an isolated top view of the additional frame section  30 , shows how the section  30  may be advantageously divided with a partition  32  into compartments  34  and  36 . 
         [0015]    As is generally conventional, the front (or engine) section  22  of the frame  20  is represented as including two lower tubular members  26  welded (or otherwise attached) to a lower portion of a neck  28 , and extending downwardly and rearwardly while diverging from one another. The engine section  22  further includes two upper tubular members  38  welded (or otherwise attached) to the upper portion of the neck  286 . The upper tubular members  38  extend rearwardly while also diverging from one another, and are welded (or otherwise attached) to the lower tubular members  26  to generally define the engine section  22 , as seen in  FIG. 2 . 
         [0016]    The transmission frame section  24  is also represented as including two upper tubular members  40  welded (or otherwise attached) to portions of the upper tubular members  28 . The tubular members  40  extend rearwardly and then downwardly, and are welded (or otherwise attached) to rearward potions of the lower tubular members  26 . As previously noted, principal functions of the transmission section  24  are to provide a support structure for the driver seat and house the motorcycle transmission (not shown). 
         [0017]    The additional frame section  30  of this invention is schematically represented as including two upper tubular members  42  welded (or otherwise attached) to upper portions of the upper tubular members  40 . The tubular members  42  extend rearwardly and then downwardly, where they are welded to rearward portions of the lower tubular members  26 . 
         [0018]    As evident from  FIG. 2 , a notable function of the frame section  30  is to accommodate and support the passenger seat in front of the rear wheel  18 . Additional benefits include the ability to provide additional storage space, shown in  FIGS. 3 and 4  as being divided into two separate compartments  34  and  36  by the partition  32 , such as a wall or plate oriented vertically within the section  30 .  FIGS. 3 and 4  represent the frame section  30  as further including spacers  44  to laterally brace the frame section  30 . 
         [0019]    The partition  32  is represented as welded or otherwise attached to the spacers  44 . In addition to providing structural reinforcement, the partition  32  can also serve as structure for mounting for various electrical and mechanical components of the motorcycle, such as rectifiers and circuit breakers  46 , a battery  48 , and an air pump  50 . 
         [0020]    In  FIG. 2 , the position of a passenger is seen in relation to the frame section  30 . Relative to the conventional frame  10  of  FIG. 1 , the passenger is lowered in front of the rear wheel  18  in relation to the prior art frame of  FIG. 1 . The inclusion of the frame section  30  is notably advantageous because it lowers the combined center of gravity of the motorcycle and its riders, including the passenger, to permit better operational and handling performance. In addition, accommodating the passenger seat on the frame section  30  in front of the rear wheel  18  provides the additional advantage of reducing wind drag that results from a passenger sitting on a passenger seat located above the rear wheel  18 , as evident from  FIG. 1 . Finally, the separate storage compartments  34  and  36  with the frame section  30  provide the advantage of keeping electrical and mechanical devices separate and farther from the engine to reduce the heating effect of the engine. 
         [0021]    While the invention has been described in terms of a specific embodiment, it is apparent that other forms could be adopted by one skilled in the art. For example, the physical configuration of the frame  20  and its individually sections  22 ,  24 , and  30  could and likely would differ significantly from that schematically represented in  FIGS. 2 ,  3 , and  4 , and various materials and processes could be used to fabricate the frame  20 . Furthermore, while the sections  22 ,  24 , and  30  of the frame  20  are represented and described as being individually constructed and then assembled together, it is foreseeable that one or more of the sections  22 ,  24 , and  30  could be molded or otherwise fabricated as a single unit, such that the entire frame  20  could have a more integrated construction. Therefore, the scope of the invention is to be limited only by the following claims.