Abstract:
A motorcycle frame and motorcycle built thereon, the frame having a longitudinal frame assembly with a cradle assembly depending therefrom, the cradle assembly adapted to support rider foot pegs and to provide a lower mount for an engine. The cradle assembly supports the weight of the engine, which is held in a substantially horizontal orientation, and provides a strong support for the rider foot pegs.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention pertains to motorcycles and motorcycle frames and, more particularly, to a frame adapted to support a horizontally-oriented engine, rider foot pegs, and, when used, at least one foot-actuated brake pedal.  
         [0003]     2. Description of the Related Art  
         [0004]     Virtually all motorcycles have an engine in which at least one cylinder is oriented either vertically or horizontally. A horizontal four-stroke cylinder engine has a piston stroke that runs parallel or substantially parallel to the ground. As shown in  FIG. 1 , a convention motorcycle frame  20  is shown in which a four-stroke engine  22  is attached thereto. The frame  20  is a typical backbone-style frame in which the engine  22  is supported at two or three points, one or two at the top  24  of the engine  22  and the other at the back  26  of the engine  22 . This frame style has a single or multiple tubes  28  that run longitudinally from a rear swing arm (not shown) located behind the engine  22 , up and over the engine  22  to a front head tube  30  where front forks suspension and handle bars are attached. The engine  22  is mounted in such a way that it is suspended or hanging from the frame  20  only by two, three, or four mounting points on the top and back. It has no support or protection at the bottom of the engine  22 .  
         [0005]     The foot peg bracket  32  on these motorcycles is attached by bolts (not shown) to the bottom of the engine  22  itself and is not supported by the frame  20  in any way. The foot peg bracket  32  (shown in  FIG. 2 ) is part of the motorcycle that the actual foot peg mounts  34  where the foot pegs would be mounted. The foot peg bracket  32  supports nearly 100% of a rider&#39;s weight when the rider is standing during riding, and this weight is transferred directly from the foot peg mounts  34  to the foot peg bracket  32  and then to the engine  22 . On current horizontal-engine motorcycles, the foot peg bracket  32  is attached to the bottom of the motorcycle engine case  36  by bolts, typically four bolts (not shown). These engine cases  36  are typically made of cast aluminum and are easily broken.  
         [0006]     In short, on horizontal-engine motorcycles, the weight of the rider is supported only by the cast aluminum engine cases. Failure can be expensive and dangerous for the owner or rider. This is because many of these horizontal-engine motorcycles are ridden off-road in rough terrain or in competition. When failure occurs on the engine cases where the foot peg bracket  32  is attached, the foot peg mounts  34  and foot peg bracket  32  (typically made of steel) break the bottom of the aluminum motor case  36  and the rider&#39;s feet/legs are allowed to contact the ground. This will destroy expensive motor cases and is extremely dangerous for the rider when failure occurs while traveling at any slow speed.  
         [0007]     When failure occurs to the engine cases on the suspended motor mounting system (because the engine is suspended from the frame), the engine cases break at the top, allowing the entire engine to break loose from the frame. This destroys expensive engine cases and will cause the rider and the engine to fall to the ground. Not only is this expensive, it is also very dangerous to the rider and to nearby riders.  
       BRIEF SUMMARY OF THE INVENTION  
       [0008]     A motorcycle frame and corresponding motorcycle are provided in the disclosed embodiments of the invention described herein. In one embodiment of the invention, a motorcycle frame is provided that includes a longitudinal frame assembly and a cradle frame assembly depending from the longitudinal frame assembly and adapted to support rider foot pegs and to provide a bottom engine mount for the engine to hold the engine in a horizontal orientation. It is to be understood that while the present invention is described in the context of a horizontal engine, it will have application to vertically-oriented engines.  
         [0009]     In accordance with another embodiment of the invention, a frame for supporting an engine having a reciprocating piston is provided, the frame including a subframe assembly and a frame spar depending from the subframe assembly, the frame spar comprising an engine mount adapted to support the engine such that the piston stroke is within a range of ±45° of horizontal.  
         [0010]     In accordance with the foregoing embodiment, at least one foot peg mount is provided, and preferably two. Ideally, the subframe assembly and the frame spar are integrally formed and the subframe assembly includes at least one upper engine mount and the frame spar includes at least one rear engine mount and one lower engine mount.  
         [0011]     In accordance with another embodiment of the invention, a frame for supporting a horizontally-oriented engine is provided, the frame includes a mounting assembly and an assembly for holding an engine in a horizontal position, the holding assembly having an association with the mounting assembly. Ideally, the holding assembly includes at least one spar extending from the mounting assembly, and the mounting assembly is adapted to mount at least one from among a fender, a seat, a shock absorber, a gas tank, a fork, and a steering mechanism. The holding assembly is ideally adapted to mount at least one from among a brake pedal, a brake cylinder, at least one foot rest, and a swing arm.  
         [0012]     In accordance with another embodiment of the invention, a frame for a motorcycle adapted to support at least one from among a seat, a front wheel fork, a steering mechanism, a swing arm, a fender, a chain roller, a shock absorber, a gas tank, at least one foot rest or foot peg, a brake pedal, a brake cylinder, and an engine having at least one reciprocating piston, the frame including a subframe assembly comprising at least a subframe and at least one side tube; and an engine mount depending from the subframe assembly. Ideally, the engine mount is configured to hold the engine so that the piston reciprocates in a direction at least ± 45 ° of horizontal.  
         [0013]     In accordance with another embodiment of the invention, a frame for supporting an engine and at least one foot peg, the frame including a subframe assembly and a cradle depending from the subframe assembly, the cradle adapted to support the engine and to support the at least one foot peg.  
         [0014]     In accordance with another embodiment of the invention, a motorcycle is provided that includes a motorcycle frame having a longitudinal assembly and a cradle assembly extending from the longitudinal assembly and adapted to hold an engine and at least one foot peg.  
         [0015]     In accordance with another embodiment of the invention, a motorcycle frame for horizontal four-stroke engines is provided that incorporates a structural design and cross-section system that supports the lower side of the engine and strengthens the unsupported and inadequate foot peg mounting bracket by relocating the foot peg stress to the new support structure, thus providing increased durability and safety for horizontal engine motorcycles. The motorcycle frame includes a unique frame structure and cross-section system designed to support the lower side of a horizontal engine and to strengthen the foot peg mounting bracket by relocating the foot peg stress to the new support structure. Thus, the unique frame design combines the mounting of the engine through a foot peg cross-section to the frame.  
         [0016]     As will be readily appreciated from the foregoing, the frame of the present invention and resulting motorcycle corrects both of the issues listed above by supporting the horizontal four-stroke engine from the bottom and incorporating the foot peg bracket mounting system through the frame itself. This adds durability and safety by the nature of its design. More particularly, this design maintains the correct relationship of the engine to the critical meeting components, such as the rear sprocket, rear brake system, brake pedal, kick-starter arm, rear shock absorber, engine system, and other components, including the drive chain or drive belt.  
         [0017]     The frame design and motorcycle of the present invention provide improved engine support by incorporating an additional engine support location that cradles the lower side of the engine. This additional mounting point substantially reduces weight stress on the upper motor mounts by distributing the weight stress to the new lower engine mount in the cradle, eliminating the “suspended” engine position. Thus, the weight of the engine and the motorcycle rider are supported by the frame as the new design allows the engine to sit upon and be bolted to the new support system that is incorporated in the structure of the frame itself. The combined engine and rider weight are no longer suspended only by mounting points from the top of the engine. The new frame allows the weight of the engine and the rider to now be supported from below in addition to from above, which protects the engine from dropping to the ground should the upper motor mounts fail.  
         [0018]     In addition to support for the engine, the frame design of the present invention incorporates the foot peg mounting system into the same frame support system. The new design can use the existing foot peg bracket or eliminate the bracket altogether. Due to the engine support by the new frame of the present invention, the stress is minimized on the engine cases, which is normally caused by the weight of the foot peg mounts because the foot peg bracket is now mounted through the frame instead of only to the engine. The new frame design of the present invention also utilizes the mounting holes in the engine case where the foot peg mount is traditionally bolted to the engine case. A new cross-section plate is supported by the new frame structure from the sides, creating a solid structure for both the engine and the foot pegs because both are now attached directly to the frame. The entire foot peg structure is now supported by the mounting plate bolted to the engine cases through the frame and is supported by the frame structure itself.  
         [0019]     In order to incorporate the structure engine and foot peg support, the entire frame of the present invention has been engineered from the head-tube to the subframe assembly as described in more detail below. Thus, the frame design of the present invention and resulting motorcycle provide improved durability, fewer problems with expensive broken motor mounts and damaged engine cases, and improved rider safety by reducing the risk of failure that may result in injury to the rider. 
     
    
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS  
       [0020]      FIG. 1  is a side view of a traditional backbone-style motorcycle frame with engine;  
         [0021]      FIG. 2  is a bottom plan view of the traditional motorcycle frame and engine of  FIG. 1 ;  
         [0022]      FIG. 3  is an isometric projection from a top side view of a motorcycle frame formed in accordance with one embodiment of the present invention;  
         [0023]      FIG. 4  is a top plan view thereof;  
         [0024]      FIG. 5  is an elevational front view thereof;  
         [0025]      FIG. 6  is an elevational rear view thereof;  
         [0026]      FIG. 7  is an elevational view of a first side thereof;  
         [0027]      FIG. 8  is an elevational view of a second side thereof;  
         [0028]      FIG. 9  is a bottom plan view thereof;  
         [0029]      FIG. 10  is an isometric projection of another embodiment of a motorcycle frame formed in accordance with the present invention;  
         [0030]      FIG. 11  is a side view of the embodiment of  FIG. 10  showing an engine mounted thereon;  
         [0031]      FIG. 12  is a partial enlarged view of the frame and engine of  FIG. 11 ;  
         [0032]      FIG. 13  is a bottom plan view of the frame and engine assembly of  FIG. 11 ;  
         [0033]      FIG. 14  is an isometric projection of a top side view of another embodiment of a motorcycle frame formed in accordance with the present invention;  
         [0034]      FIG. 15  is a top plan view thereof;  
         [0035]      FIG. 16  is an elevational front view thereof;  
         [0036]      FIG. 17  is an elevational rear view thereof;  
         [0037]      FIG. 18  is an elevational view of a first side thereof;  
         [0038]      FIG. 19  is an elevational view of a second side thereof; and  
         [0039]      FIG. 20  is a bottom plan view thereof. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0040]     A representative embodiment of the present invention will now be described in conjunction with  FIGS. 3-9 . As shown therein, a frame  40  that, in this embodiment, has a longitudinal frame assembly  42  that includes a subframe  44  and perimeter side tubes  46  attached to or formed with a cradle assembly  48 . As shown in this embodiment, the subframe  44  is attached to a rear gas tank mount  50  that in turn is coupled to the cradle assembly  48 . A forward gas tank mount  52  is located behind a head tube  54  at a forward end of the side tubes  46 . Depending from the head tube  54  is a steering stop  56 . An upper engine mount  58  in the form of a pair of lugs  60  extends from the cradle assembly  48  where the side tubes  46  meet the cradle assembly  48 . A rear fender mount  62  is located on the U-shaped subframe  44 , and a brace  64  for the subframe  44  extends from both sides  66  of the U-shaped subframe  44  down to the cradle assembly  48 .  
         [0041]     The cradle assembly  48  is, in this embodiment, formed of a pair of frame spars  68  that, as shown in  FIG. 1 , extend away from the longitudinal frame assembly  42  and have a pair of legs  70  that curve toward the front in the direction of the head tube  54 . Attached to each frame spar  68  is the brace  64 . In addition, a lower engine mount  72  is located at a distal end of the frame spar legs  70 . Foot peg mounts  74  are shown attached to the legs  70 . Alternatively, the lower engine mount  72  may be integrally formed with the foot peg mounts  74  or attached with the separate foot peg mounts using the same fastener or other suitable hardware or by welding or other known methods. In another embodiment, foot pegs can be mounted directly to the legs or to the lower engine mount or both without using a foot peg mount. Another method is to attach the foot peg mount  74  through the leg  70  and into the engine case, although that is not preferred due to risk of damage to the engine case. In one embodiment, the foot peg mounts  74  extend through the frame spar legs  70  into the lower engine mount  72 , and the lower engine mount  72  is attached to each leg  70  with two bolts. The foot pegs themselves are then mounted to the foot peg mounts  74  with a pin and clip (not shown) as is known in this technology.  
         [0042]     A rear engine mount  76  is shown positioned between the frame spars  68  in such a manner that it is “floating.” In other words, the rear engine mount  76  is not attached directly to the frame spars  68 , but instead is dimensioned to have a width less than the width between the frame spars  68  to create a space for the insertion of a rear swing arm (not shown) to which is mounted the rear wheel of the motorcycle. The rear engine mount is considered optional in some embodiments, providing additional stability to the mounting of the engine.  
         [0043]     The legs  70  of the frame spars  68  are designed to curve forward, and the degree of projection and the amount of curvature between the legs  70  and the upper portion of the frame spar  68  is a matter of design, as is the exterior configuration of the frame spars  68 . The position of the lower engine mount  72  on the legs  70  can be made adjustable to position the engine at a desired horizontal orientation in the range of ±45° from horizontal. A preferred range is, in one embodiment, between ±10°, and in another embodiment between ±5° of horizontal. It is to be understood that other ranges, such as ±15°, ±20°, ±25°, ±30°, and ±35° may also be used depending on the engine style and size, and the nature of the use of the motorcycle.  
         [0044]     In addition to the foregoing, the cradle assembly  48  also includes a rear brake master cylinder mount depending from one of the frame spars  68 , in this case from the right frame spar as shown in  FIG. 3 . A brake pedal mount  80  for a foot-actuated brake pedal (not shown) is also formed on the cradle assembly  48 , and as shown in  FIGS. 3-9 , is associated with the right frame spar  68 . The brake pedal mount  80  can be associated or formed to be integral with the brake cylinder mount  78 .  
         [0045]     In construction, the frame is preferably formed of metal, such as aluminum, chromoly, steel, or other metal or a combination thereof, with each assembly component welded together to form a rigid structure. However, it is to be understood that other methods of attachment may be used, including fasteners, tightly-fitted joints, and other methods known to those skilled in the art.  
         [0046]      FIG. 10  illustrates an alternative embodiment in which the subframe  44  and brace  64  are not shown. In addition, the foot peg mounts  74  are also not shown on the cradle assembly  48 .  
         [0047]      FIGS. 11-13  illustrate the frame  82  of  FIG. 10  having an engine  84  mounted thereon. For ease of reference and sake of simplicity, the same reference numbers are used for common components among the different embodiments. Here, the engine casing  86  is attached to the lower engine mount  72  and the upper engine mount  58 . In addition, as an optional mounting, the rear engine mount  76  can also be used as shown in  FIG. 12 . As can be seen in  FIG. 11 , the cylinder head  88 , in which a piston is mounted to reciprocate, is oriented substantially in a horizontal position. This means relatively horizontal with respect to the earth.  
         [0048]      FIGS. 14-20  illustrate yet another embodiment of the invention. For ease of reference, elements common to the other embodiments will bear the same reference numbers.  
         [0049]     As shown in these  FIGS. 14-20 , a motorcycle frame  90  is presented similar in some respects to the appearance and function of the motorcycle frames  40  and  82  previously described. This third embodiment includes a longitudinal frame assembly  92  having a modified subframe  94  and the perimeter side tubes  46  coupled to the cradle assembly  96 . The subframe  94  in this design utilizes a pair of rails  98 , preferably tubular in shape, although other shapes may be used to accomplish the same purpose. The rails are attached to the rear gas tank mount  50 . The brace  64  extends from the subframe  94  to the cradle assembly  96 , and in particular to the frame spars  100  that have lower legs  102  depending therefrom. The legs  102  extend toward the front or head tube  54  to be positioned below the side tubes  46 . A lower engine mount  104  is positioned between the distal end of the legs  102 . A rear engine mount  106  is shown floating between the frame spars  100  in a manner described previously with respect to the motorcycle frame  40  and the rear engine mount  76 . A pair of upper engine mounts  106  depend from the side tubes  46 .  
         [0050]     In this embodiment, the motorcycle frame  90  is sized to accommodate a different engine (not shown). Thus, the length of the frame spars  100  and legs  102  will, for the most part, be dictated by the size of the engine. However, the particular shape of the frame spars  100  and legs  102  is a matter of design choice, including the arc of curvature of the legs  102  at the intersection  108  with the upper portion of the frame spars  100 , the rounded nature of the exterior surface of the frame spars  100  and legs  102 , as well as of the side tubes  46 , the subframe  94 , and the braces  64 . It is to be understood that other aesthetic shapes may be used without compromising the structural integrity of the frames described herein.  
         [0051]     Foot pegs (not shown) may be mounted directly to the ends of the legs  102 . Although separate foot peg mounts are not shown in connection with this embodiment of the invention, it is to be understood that foot pegs mounts  74  used with the first frame  40  may be mounted on the outside of the legs  102 . And as with the previous embodiments, each of the components may be coupled together via welding, fasteners, tight fit junctions, and other methods known to those skilled in the art.  
         [0052]     All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, are incorporated herein by reference, in their entirety.  
         [0053]     From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.