Patent Publication Number: US-2018043967-A1

Title: Motorcycle Engine Mount having Improved Stiffness and Exchangeability

Description:
This application is a continuation of application Ser. No. 14/634,227, filed Feb. 27, 2015, now pending (hereinafter “the Parent Application”). 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to motorcycle frame and mounting components and, more specifically, to a Motorcycle Engine Mount having Improved Stiffness and Exchangeability. 
     2. Description of Related Art 
     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. 
     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. 
     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. 
     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 
     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). Unlike the device of the Parent Application, the urethane interstitial element should not be bonded to the outer frame element so that the urethane interstitial element can be slid out of the outer frame and replaced, if desired. The interstitial element should protrude from the outer frame, and should not reach the full depth of the outer frame depth. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       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: 
         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. 
         FIG. 2  is a front perspective view of the conventional engine mount element for an FXD —  series motorcycle; 
         FIG. 3  is a rear perspective view of the engine mount element of  FIG. 2 ; 
         FIG. 4  is a front perspective view of the Engine Mount having Improved Stiffness of the Parent Application; 
         FIG. 5  is a rear perspective view of the element of  FIG. 4 ; 
         FIGS. 6A and 6B  are front perspective views the Improved Engined Mount having Improved Stiffness and Exchangeability; 
         FIG. 7  is a side view of the Mount element of  FIGS. 6A and 6B ; 
         FIG. 8  is an exploded rear perspective view of the Mount element of  FIGS. 6A and 6B ; and 
         FIG. 9  is a rear perspective view of the Mount element of  FIGS. 6A and 6B . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     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 and Exchangeability 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. 
     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. 
       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 ]. 
     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. 
     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 . The rubber interstitial element  26  “sticks” to the engine attachment frame  22  in some fashion, but this interconnection has been found to be unreliable. 
     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. 
       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. 
       FIG. 4  is a front perspective view of the Engine Mount having Improved Stiffness of the Parent Application. 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. 
     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. 
     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. 
     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 . 
     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 . 
       FIG. 5  is a rear perspective view of the element  30  (of the Parent Application) 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. 
     After substantial real-world use and testing of the element  30 , Applicant determined that the performance remained inconsistent. While it was still vastly superior to the Original Equipment engine mount, it still tended to allow vibrations to pass from the engine to the frame. Consequently, a redesign of the device was undertaken.  FIG. 6  provides additional detail of the resultant improved design. 
     The present invention can best be understood by consideration of  FIGS. 6A and 6B .  FIGS. 6A and 6B  are front perspective views the Improved Engine Mount having Improved Stiffness and Exchangeability  50 . There are several distinctions between this element  50  and the element [ 30 ] of the Parent Application. This mount  50  is oval in shape, rather than rectangular. There are no front and rear backing plates. A harder urethane material is used for this device (an  80  durometer reading, rather than a  55  durometer reading). A key difference is that the urethane intersitial element  56  is not bonded to the engine attachment frame  52 , but rather is unattached to the frame  52  in any permanent way. As will be discussed further below, this lack of bonding between the elements means that the interstitial element  56  can be removed and replaced without the need to replace the entire mount  50 . 
     The engine bolt bores  24  are located so that they correspond to the Harley Davidson original equipment engine. The engine attachment frame  52  now has an oval shape, rather than a rectangular shape (as both the OEM and the mount of the Parent Application had). It was determined that the oval shape provided more consistent, reliable cushioning and support for the engine in all 360 degrees of possible motion (i.e. vibration or torque-driven movement). 
     As is depicted in  FIG. 6B , the frame attachment element  54  extends forward from the front of the engine attachment frame  52 —this distance is effectively the same as with the device [ 30 ] of the Parent Application. What is different is that the frame attachment element  54  is not bare, unsupported metal in this extended portion. On the contrary, there is a tapered portion  60  of the interstitial element  56  that extends between the shoulder portion  58  (against the face of the frame  52 ) and the face of the frame attachment element  54 . The tiered tapering of the urethane that makes up the interstitial element  56  results in a varying level of stiffness in the support provided by the interstitial element  56  to the frame attachment element  54  over the extent of the protruding element  54 . As the distance from the shoulder portion  58  increases, the thickness of the urethane reduces, and the stiffness of the support also reduces. Testing has revealed that this geometry provides the benefit of reliable support for the frame attachment element  54 , while also giving very good vibration isolation between the engine and frame. If we now turn to  FIG. 7 , we can continue to examine this improved system. 
       FIG. 7  is a side view of the Mount element  50  of  FIGS. 6A and 6B . The frame element  52  is defined by a rear face  66  and a front face  67 . The face  62  of the interstitial element  56  protrudes beyond the face  67  of the frame element  52  by extension distance  64 . Over that distance, the outer perimeter of the interstitial element  56  tapers in a tiered manner, starting from the shoulder portion  58 , through the tiered taper portion  60 , and terminating at the face  62 . Other unique aspects of the instant design are shown in  FIGS. 8 and 9 . 
       FIG. 8  is an exploded rear perspective view of the Mount element  50  of  FIGS. 6A and 6B , and  FIG. 9  is rear perspective view of the fully assembled mount element  50 . The shoulder portion  58  has an outer diameter (around its oval shape) that is greater than the outer diameter of the perphery of the engine attachment frame element  52 . Consequently, the shoulder portion  58  prevents the tapered portion [ 60 ] from being inserted into the central bore  74  of the frame element  52 . The shoulder rear face  68  defines the surface where the diameter of the intersititial element  56  expands beyond the sidewall  70  of the internal portion of the interstitial element  56 . The shape and outer diameter of the sidewall  70  is configured to cooperate with the central bore  74  of the frame element  52  so that the interstitial element  56  will slip into the central bore  74  until the shoulder rear face  68  reaches the frame front face [ 67 ]. At this point, as depicted in  FIG. 9 , the interstitial element  56  does not reach the rear face  66  of the frame element  52 . Since the depth of the sidewall  70  of the captured portion  75  of the interstitial element  56  is less than the depth of the inner wall  76  of the central bore  74 , a rear standoff distance  78  is left between the rear faces  66  and  72 . 
     The rear standoff distance  78  between the rear faces  72  and  66  results in two benefits: (a) the interstitial element  54 / 56  can be more easily removed and re-inserted into the outer frame  52  because there is less friction between the inner wall [ 76 ] and the interstitial element sidewall [ 70 ]; and (b) the reduction in material results in a decrease in weight for the overall element [ 50 ]. 
     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.