Abstract:
A Motorcycle Engine Mount having Improved Stiffness. The device is a bolt-in replacement for the Original Equipment Manufacturer engine mounts for FXD_series Harley Davidson motorcycles. The device has a single-piece, hardened steel outer frame, and a interstitial formed from urethane (rather than rubber) having a durometer reading of 40-60. The outer frame and inner frame attachment elements are both formed with a plurality of apertures through them so that they will be infilled with urethane when the urethane is injected to form the interstitial element. This infilling will bond the three elements together for long-term durability. There are also front and rear retention plates made from hardened metal to further stabilize and bond the inner frame attachement element to the urethane interstitial element.

Description:
[0001]    This application is filed within one year of, and claims priority to Provisional Application Ser. No. 61/945,493, filed Feb. 27, 2014. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    This invention relates generally to motorcycle frame and mounting components and, more specifically, to a Motorcycle Engine Mount having Improved Stiffness. 
         [0004]    2. Description of Related Art 
         [0005]    The popularity of motorcycling continues to increase. Riders are attracted to the freedom of the open road, leaving behind the cares and worries of everyday life. Motorcycle manufacturers have seized upon the recent surge in popularity and continue to sell motorcycles and accessories in record numbers. 
         [0006]    However, statistics show that motorcycles are generally more dangerous than automobiles. Two prior patents granted to Jake Ore (U.S. Pat. Nos. 7,967,097 and 8,387,737) address the issue with Harley Davidson 1  motorcycles commonly referred to as a “high-speed wobble” (or “tank-slapper”), which typically involves shaking or instability. This wobble can cause the front wheel can thrash from side to side in an uncomfortable and unsafe manner. The devices and methods of the &#39;097 and &#39;737 patents cured the high-speed wobble on the “FLH” series of Harley Davidson motorcycles (known as the “Electra Glide,” “Road King,” and “Ultra Classic).  1  The Specification may include references to third-party trademarks, and copies of third-party copyrighted materials, which are the property of their respective owners, including H-D U.S.A., LLC. Reference to any product, process, publication, service, or offering by trade name, trademark or otherwise is not intended to constitute or imply the endorsement or recommendation of such by Harley-Davidson. “Wide Glide,” “Electra Glide,” and “Road King” trademarks are believed to be the property of H-D U.S.A., LLC. 
         [0007]    It has been determined that two other models Harley Davidson—the “Wide Glide” and “Ultra Glide” (the “FXD_” series), suffer from a very similar problem. Because the FXD_series bikes employ a different mounting system as compared to the FLH series bikes, the two prior Ore devices were unable to solve the high speed wobble on these models of motorcycles. 
         [0008]    Therefore, there remains a need to overcome the problem of instability in FXD_series HarleyDavidson motorcycles. The discussion of the background to the invention included herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material referred to was published, known, or part of the common general knowledge at the priority date of the claims. 
       SUMMARY OF THE INVENTION 
       [0009]    In light of the aforementioned problems associated with the prior devices, it is an object of the present invention to provide a Motorcycle Engine Mount having Improved Stiffness. The device should be a bolt-in replacement for the Original Equipment Manufacturer engine mounts for FXD_series Harley Davidson motorcycles. The device should have a single-piece, hardened steel outer frame, and a interstitial formed from urethane (rather than rubber). The outer frame and inner frame attachment element should both be formed with a plurality of apertures through them so that they will be infilled with urethane when injected to form the interstitial element. This infilling will bond the three elements together for long-term durability. There should further be front and rear retention plates made from hardened metal to further stabilize and bond the inner frame attachement element to the urethane interstitial element. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]    The objects and features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages, may best be understood by reference to the following description, taken in connection with the accompanying drawings, of which: 
           [0011]      FIG. 1  is a perspective view of the Harley Davidson FXD_series frame and engine mount assembly 2 ;  2  Taken from the 2007 Harley Davidson Shop Manual; used for educational purposes only; all rights believed owned by Harley Davidson, Inc. 
           [0012]      FIG. 2  is a front perspective view of the conventional engine mount element for an FXD_series motorcycle; 
           [0013]      FIG. 3  is a rear perspective view of the engine mount element of  FIG. 2 ; 
           [0014]      FIG. 4  is a front perspective view a preferred embodiment of the engine mount element having improved stiffness of the present invention; 
           [0015]      FIG. 5  is a rear perspective view of the element of  FIG. 4 ; 
           [0016]      FIG. 6  is a front perspective view of the engine attachment frame of the element of  FIGS. 4 and 5 ; 
           [0017]      FIG. 7  is a front perspective view of the frame attachment element and retention plates of the element of  FIGS. 4 and 5 ; and 
           [0018]      FIG. 8  is a flowchart depicting a preferred method of manufacture of the engine mount element of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0019]    The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor of carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the art, since the generic principles of the present invention have been defined herein specifically to provide a Motorcycle Engine Mount having Improved Stiffness 3 .  3  As used throughout this disclosure, element numbers enclosed in square brackets [ ] indicates that the referenced element is not shown in the instant drawing figure, but rather is displayed elsewhere in another drawing figure. 
         [0020]    We will begin the description of the invention by first examining the features of the prior art Harley Davidson FXD_series motorcycle.  FIG. 1  is a perspective view of the Harley Davidson FXD_series frame and engine mount assembly  10 . In order to isolate and dampen the vibrations generated by the running engine, the engine (not shown) is linked to the frame  11  by a pair of engine mount elements  12 A,  12 B. Each mount  12 A,  12 B attaches to the frame  11  by a pair of frame bolts  14 A,  14 B (only shown for the rear engine mount element  12 B). The engine (not shown) then attaches to each of the mounts  12 A,  12 B by a pair of engine bolts  16 A,  16 B. As will be discussed in connection with  FIGS. 2 and 3 , there is a rubber portion separating the frame bolts  14 A,  14 B from the engine bolts  12 A,  12 B. It is this rubber (provided for vibration dampening) that is insufficiently stiff, and therefore allows for unacceptable amounts of wobbling or shaking in the motorcycle under certain riding conditions. 
         [0021]      FIG. 2  is a front perspective view of the conventional engine mount element  12 A,  12 B for an FXD_series Harley Davidson motorcycle. The outer structure is an engine attachment frame  22 . This frame  22  is made from stamped steel, presumably for its durability. In this version, there are three individual pieces of stamped steel that have been riveted together. Captured inside of the engine attachment frame  22  is a frame attachment base  18 . The frame attachment base  18  has a pair of threaded bolt bores  20 A,  20 B formed within it. These bores  20 A,  20 B are adapted to accept the frame bolts [ 14 A,  14 B] within them when the mount element  12 A/ 12 B is attached to the frame [ 11 ]. 
         [0022]    The engine bolt bores  24  are provided to accept engine bolts [ 16 A,  16 B] through them as they pass through corresponding bores formed in the engine (for mounting the engine to the mounting element  12 A,  12 B. 
         [0023]    The problem area with the conventional engine mount elements  12 A,  12 B, lies with the rubber interstitial element  26 . This rubber “fills” the gap between the engine attachment frame  22  and the frame attachment base  18 . The rubber interstitial element  26  serves to prevent vibrations from being transmitted between the frame attachment base  18  and the engine attachment frame  22 . By design, the rubber element  26  also secures and supports the frame attachment base  18  within the engine attachment frame  22 . 
         [0024]    The problem with the conventional mount elements  12 A,  12 B is that after very little time in service, this rubber interstitial element  26  becomes pliable and the frame attachment base  18  is no longer held securely within the engine attachment frame  22 . The movement allowed between these elements results in a loose connection between the engine and the frame [ 11 ], which causes the wobbling under many riding conditions. 
         [0025]      FIG. 3  is a rear perspective view of the engine mount element of  FIG. 2 . This view is provided to illuminate the fact that the back of the frame attachment base [ 18 ] does not protrude through the rubber interstitial element  26 , but rather is fully encased in rubber (on three sides). As will be discussed below, this design error has been corrected with the device of the present invention. 
         [0026]    The present invention can best be understood by consideration of  FIG. 4 .  FIG. 4  is a front perspective view a preferred embodiment of the engine mount element having improved stiffness  30  of the present invention. Of course, the improved mount element  30  is designed to fit the frame [ 11 ] perfectly as a replacement for the conventional mounts [ 12 A,  12 B]. It is there that the similarities end between the two designs, as will become clearer below. 
         [0027]    The improved mounting element  30  has a one-piece engine attachment frame  32 . It is formed from a single piece of hardened steel in order to ensure that there is virtually no degradation (i.e. deformation) after prolonged service time. The frame attachment element  38  protrudes from the mount element  30  just as with the prior design, and furthermore has the pair of threaded frame bolt bores  20 A,  20 B formed within it. 
         [0028]    The interstitial element  34  in this mount  30  is made from a high quality urethane, instead of the rubber material used in the prior design. The urethane material  34  has superior wear performance as compared to rubber (i.e. it remains stiff much longer), and this particular urethane has been selected to have a durometer reading (A scale) of between 40 and 60 (A scale). It is preferred that the front mount [ 12 A] urethane have a 45 durometer reading, and the rear mount [ 12 B] urethane have a 55 durometer reading. 
         [0029]    Two key additional features can be seen in this view—first, the engine attachment frame  32  is formed with retaining apertures  36 A formed in it (there are actually five in the entire frame  32 ). Each retaining aperture (e.g.  36 A) is designed to allow the urethane forming the interstitial material  34  to push out and fill in the aperture  36 A. Once cured, this protruding material will form a secure bond between the interstitial element  34  and the engine attachment frame  32 . 
         [0030]    A second feature seen here is the inclusion of the front retention plate  40 A. As shown, the head of the frame attachment element  38  protrudes through an aperture formed in the front retention plate  40 A. The retention plate  40 A serves to further bond with the interstitial element  34 , while also stabilizing the restraining the frame attachment element  38  within the engine attachment frame  32 . These two features, when combined with the use of urethane instead of rubber, serve to make the engine mount  30  substantially more durable and long-lasting.  FIG. 5  shows the other side of the mount  30 . 
         [0031]      FIG. 5  is a rear perspective view of the element  30  of  FIG. 4 . In this view, the urethane of the interstitial element  34  can be seen protruding into the pair of retaining apertures on this (opposing) side of the engine attachment frame  32 . The frame attachment element  38  actually protrudes from the back side of the urethane interstitial element  34 . Like the other end of the frame attachment element  38 , the rear retention plate  40 B is embedded in the urethane material in order to firmly secure the element  38  within the urethane.  FIG. 6  provides additional detail. 
         [0032]      FIG. 6  is a front perspective view of the engine attachment frame  32  of the engine mount element [ 30 ] of  FIGS. 4 and 5 . As can be seen, the frame  32  is formed from a single piece of hardened steel that has been cut and then bent into shape. As a result, there are no mechanical connectors between components of the frame  32 —it is a single unitary piece. 
         [0033]    As can be seen, each sidewall  42  has a pair of retaining apertures formed completely through them. The bottom wall  44  has an additional retaining aperture  36 B formed through it as well. As mentioned, when the urethane material is injected into the interstitial space between the frame attachment element [ 38 ] and the engine attachment frame  32 , it will also fill in the area within these apertures  36 A and  36 B. Finally, we will turn to  FIG. 7  to examine the final details of this useful device. 
         [0034]      FIG. 7  is a front perspective view of the frame attachment element  38  and retention plates  40 A,  40 B of the element [ 30 ] of  FIGS. 4 and 5 . The element  38  is formed from a solid piece of steel, and has a retaining aperture  36 C formed through it. This aperture  36 C, like those previously discussed, fills with urethane when this material is injected into the interstitial space, and when cured, holds the element  38  firmly within the block of urethane. 
         [0035]    At the front and rear faces  47 A,  47 B of the frame attachment element  38  are formed with an adjacent shoulder  46 . The shoulder cooperates with the apertures cut into the front and rear retention plates  40 A,  40 B, so that the faces  47 A,  47 B are virtually flush with the outer surfaces of the retention plates  40 A,  40 B when the device [ 30 ] is fully assembled. 
         [0036]      FIG. 8  is provided in order to more fully illuminate the device of the present invention.  FIG. 8  is a flowchart depicting a preferred method of manufacture  60  of the engine mount element [ 30 ]. First  100 , the engine attachment frame [ 32 ] is placed into the mold cavity. The frame attachment element [ 38 ], front retention plate [ 40 A] and rear retention plate [ 40 B] are placed into the engine attachment frame [ 32 ] so that they are in spaced relation to the frame [ 32 ]. 
         [0037]    Next, the preferred urethane material is injected into the space between the engine attachment frame [ 32 ] and the other elements [ 38 ,  40 A,  40 B]  102 . As discussed above, the preferred urethane material will have an A-scale durometer hardness reading of between 40 and 60, depending upon whether it is being made as a mount element for the front of the engine or for the rear of the engine. When the material is injected, it is intentionally injected so that it fills the retaining apertures [ 36 A,  36 B] as well as the space between the frame [ 32 ] and the other elements [ 38 ,  40 A,  40 B]. 
         [0038]    Once the urethane material has sufficiently hardened, the engine mount [ 30 ] is removed from the mold  104 . 
         [0039]    Those skilled in the art will appreciate that various adaptations and modifications of the just-described preferred embodiment can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.