Abstract:
In cycling activities, riders often encounter rough terrain having various obstacles such as rocks, mounds, tree roots, and branches. These obstacles subject the bicycle&#39;s crankset and chain to extremes in stress, loading, and impact. An improved bash guard may be attached to the bicycle to protect against damage. The bash guard may include at least one rotator operatively secured to a crankset or a crank arm on the bicycle. The rotator(s) may be configured to rotate independent of the crankset rotation. The independent rotation of the rotator(s) may permit the bash guard to roll over obstacles, significantly reducing frictional sliding or rubbing between an edge of the bash guard and the obstacles.

Description:
FIELD 
       [0001]    This application relates generally to bicycle drive trains. In particular, this application relates to a bash guard for protecting a sprocket and other drive train components from damage from impact with foreign objects. 
       BACKGROUND 
       [0002]    The sport of cycling has proven to be an extremely popular and long lasting sport and recreational activity. Through the years, a wide range of participants have pursued a variety of cycling or biking activities. Not surprisingly, the various cycling or biking activities and recreations have involved a variety of environmental circumstances ranging from high speed competition to slow and casual pleasure riding or cycling. In recent years a type of cycling has emerged which is generally referred to as off-road biking or mountain biking. In this sport activity, participants often ride over extremely rough terrain and challenging hill and mountain trails. These rough terrains and trails often have various obstacles such as rocks, mounds, tree roots, branches, etc., which subject the bicycle&#39;s various components to extremes in stress, loading, and impact. 
         [0003]    For example, as shown in  FIG. 1 , the drive train on bicycle  100  could get damaged by rock  102  as bicycle  100  runs over it or when the bicycle crashes. Particularly prone to damage are the chain  104  and front crankset  106 , which includes from one to four or more variously sized sprockets, each including sprocket teeth  108 . Front crankset  106  rotates chain  104  by means of sprocket teeth  108  on the outer edges of the sprockets of crankset  106 . Teeth  108  are exposed to various obstacles, such as rock  102  or other foreign obstacle that a bicycle may encounter on rough terrain. To meet the need for protecting drive train components against damage in rough terrain environments, practitioners in the art have endeavored to provide guard devices (i.e., bash guards, chain guards) that attach to the bicycle frame, to crankset  106 , or to an outer part of crankset  106 . 
         [0004]    A conventional bash guard is typically a ring made out of a durable material such as aluminum or a polycarbonate and has a width or diameter that is larger than that of the largest sprocket in the crankset. Typically, a conventional bash guard is fixed or mounted to the bicycle with bolts and nuts or other common fasteners. A conventional sprocket-mounted bash guard is mounted to the sprockets or an outer part of the sprockets and will rotate in synchronization with the sprockets as the rider pedals. Thus, conventional sprocket-mounted bash guards can operate much like a skid plate for the bicycle. For example, the outer edge of a conventional sprocket-mounted bash guard can limit impact damage to sprockets and other components by allowing the surface of the bash guard to contact an obstacle and slide over the obstacle as the bicycle moves past the obstacle. A conventional bash guard could instead be mounted to the bicycle&#39;s frame. In this frame-mounted configuration, the bash guard remains stationary with respect to the bicycle frame and does not rotate with the rotation of the bicycle pedals. 
         [0005]    Because of their fixed nature, conventional bash guards (both sprocket-mounted and frame-mounted) often rub or slide against obstacles and, therefore, require replacement to maintain their function or appearance. Additionally, a bicycle rider may hang up on an obstacle, causing a crash, or requiring the rider to push or attempt to pedal the bicycle over the obstacle. Frame-mounted bash guards are particularly susceptible to being worn down by friction, and impact on the same point. Sprocket-mounted bash guards are also susceptible because they frequently slip or rub on hard obstacles, such as rocks or dense branches. Furthermore, when a sprocket-mounted bash guard slips laterally, even slightly, over an obstacle, this will cause the bicycle to become unstable and may cause the rider to fall and incur potentially serious injuries. 
         [0006]    One way to address the problem of frequent replacement is to form the bash guard out of an extremely durable material. However, this solution is undesirable because higher durability comes at a cost, and weight penalty. What is needed is a bash guard that resists wear and aids the rider in overcoming obstacles. The present invention remedies one or more of the problems discussed above with respect to conventional bash guards. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The following description can be better understood in light of Figures, in which: 
           [0008]      FIG. 1  is a representation of prior art of a bicycle damaged by a rock; 
           [0009]      FIG. 2  illustrates a bicycle with an embodiment of a rotating bash guard in place; 
           [0010]      FIGS. 3A-3C  illustrate different view of an exemplary embodiment of a rotating bash guard; 
           [0011]      FIGS. 4A-4B  illustrates a component of an exemplary embodiment of a bash guard; and 
           [0012]      FIG. 5  illustrates an exemplary embodiment of a rotating bash guard; Together with the following description, the Figures demonstrate and explain the principles of exemplary bash guards. In the Figures, the thickness and configuration of components may be exaggerated for clarity. The same reference numerals in different Figures represent the same component. 
       
    
    
     DETAILED DESCRIPTION 
       [0013]    An improved bash guard may be configured to rotate independently, or contain components that rotate independently of the rotation of a cycling device&#39;s crankset, causing the bash guard to roll over obstacles encountered on a rough terrain. Rolling over obstacles significantly reduces frictional sliding or rubbing between an edge of the bash guard and the obstacles. Various embodiments of an improved bash guard are described in detail below. 
         [0014]      FIGS. 2-4  illustrate some embodiments of guard  200  for mounting on cycling device  100  (e.g., a conventional bicycle, mountain bicycle, touring bicycle, racing bicycle, cruiser bicycle, street bicycle, motorcycle, moped, recumbent bicycle, tricycle, or any combination thereof, or any device with a crankset that may be exposed to damage). Bash guard  200  may protect crankset  106  and chain  104  on cycling device  100 . As shown in  FIG. 2 , crankset  106  may include various teeth  108  operable to move chain  104  in a rotational fashion. For example, a set of crank arms  120  may be mounted 180 degrees from each other and may be configured to rotate when torque is applied by a rider to either of pedals  122 . Crankset  106  may be operatively secured to crank arms  122  such that the sprockets of crankset  106  rotate with crank arms  120 . The sprockets of crackset  106  may be equipped with teeth  108 , which may engage with chain  104 , thereby transmitting rotational motion from crank arms  120  to provide a motive force to cycling device  100 . 
         [0015]    Referring again to  FIG. 2 , bash guard  200  may include a rotator  202  operatively secured to at least one of the sprockets of crankset  106 . Alternatively or in addition, rotator  202  may be operatively secured to other components, such as one or both of crank arms  120 . Rotator  202  may be positioned along or near an outer edge of crankset  106 . A diameter of rotator  202  may be greater than a diameter of the largest sprocket of crackset  106  to thereby prevent obstacles from impacting or damaging the sprockets of crankset  106  and chain  104 . 
         [0016]    Rotator  202  may be configured to rotate independent of the rotation of the sprockets and crank arms  120 . For example, when a rider pedals, turning crank arms  120  and the sprockets of crankset  106 , rotator  202  may rotate independently of crank arm  120  and sprocket rotation. If, for example, the rider goes over an obstacle that makes contact with rotator  202 , crank arms  120  and the sprockets may continue rotating in one direction while rotator  202  may rotate in an opposite direction, or may remain stationary with respect to the obstacle while crankset  106  passes over the obstacle. Similarly, crank arms  120  and crankset  106  may remain stationary with respect to bicycle  100  and the rotator  202  may rotate with respect to crankset  106  when contacting an obstacle. For example, a frictional force exerted by the obstacle contacting rotator  202  may cause rotator  202  to begin rotating. 
         [0017]    Rotator  202  may be formed with any variety of materials or combination of materials including, for example, metal (e.g., aluminum, steel, and/or titanium), plastic (e.g., polycarbonate), rubber, and others. Furthermore, an outer edge of rotator  202  may have a varied surface (e.g., knurled, grooved, bumpy) so as to increase friction with respect to obstacles encountered on a rough terrain. The varied surface may be designed for particular obstacles, for example, a grooved surface may perform best on wood obstacles to prevent rotator  202  and the sprockets from sliding in a direction normal to the direction of cycling device  100 . 
         [0018]    As shown in  FIGS. 3A-4B , bash guard  200  may also include a retainer  204  that retains or holds rotator  202  in a particular position with respect to the cycling device. Retainer  204  may be a single integral part or may include a first inner portion  205  and a second outer portion  206 . Retainer  204  may also be formed integrally with crankset  106  or any component thereof. Alternatively, retainer  204  may be secured with fasteners (e.g., bolts, nuts, screws, etc.) to one or more of the sprockets in crankset  106 , preferably to the largest, outer sprocket. Thus, when a rider applies torque to the crank arms, retainer  204  may rotate in a dependent relationship with respect to the rotation of the sprockets in crankset  106 . However, retainer  204  may loosely hold or grasp rotator  202  in a manner that permits rotator  202  to passively rotate independent of the retainer rotation. 
         [0019]    Retainer  204  may include bearings, bushings, coatings, or other friction reducing devices that may serve to operatively secure rotator  202  to retainer  204  without preventing rotator  202  from rotating independently of retainer  204  and crackset  106 . For example, retainer  204  may include a set of extruding plates arranged in a radial fashion around the edges of each of retainer portions  205  and  206 . The plates on first retainer portion  205  may be configured to line up with the plates on second retainer portion  206 , thereby forming a plurality of channels around retainer  204  along which rotator  202  may slide without falling off. 
         [0020]    The plates of retainer  204  may be configured to lightly squeeze and thereby maintain rotator  202  in a consistent position with respect to retainer  204  such that rotator  202  rotates in phase with retainer  204  and crankset  106  when no obstacles are present. Then, when rotator  202  contacts an obstacle such as rock  102 , rotator  202  may slip through the plates of retainer  204  and rotate in an independent fashion. To this end, an inner side of the plates may be lined with Teflon® tape, nylon inserts, or other lubricating elements to facilitate slipping motion with respect to rotator  202 . Alternatively, the plates may be manufactured from a material, such as a plastic or other suitable material, that allows rotator  202  to function as described. In other embodiments, bearings may take the place of the plates, or may be incorporated into the plates. 
         [0021]    A set of bolt holes  208  may be formed in bottom portions of each of the plates on retainer  204 . Rotator  202  may be secured between first and second retainer portions  205  and  206  with bolts threaded through bolt holes  208 . Bolt holes  208  may also be aligned with corresponding holes in crankset  106 , such that a single set of bolts may secure retainer portions  205  and  206  together while also securing both retainer portions to one or more sprockets in crankset  106 . Thus, rotator  202  may be held securely and rotatably with respect to retainer  204 . 
         [0022]      FIG. 5  is a perspective view of another embodiment bash guard  300  for mounting on cycling device  100 . Similar to bash guard  200  in  FIGS. 2-4B , bash guard  300  may include a retainer  304 . Retainer  304  may include mating inner and outer portions  305  and  306  secured together with bolts via a set of bolt holes  308 . Retainer  304  may also be configured to secure a plurality of rotators  302  between retainer portions  305  and  306 . A plurality of bearings  310  may secure rotators  302  to retainer  304  and each of the plurality of rotators  302  may rotate independent of the rotation of the sprockets and the crank arms of the cycling device. Various additional features may also be present. For example, retainer portions  305 ,  306  may be detachable (as shown by exemplary dashed lines) to permit replacement or repair of one or more rotators  302 , bearings  310 , or other components. In addition, rotators  302  may be formed of materials similar to that of rotator  202  in the first embodiment described in  FIG. 2 . Each of rotators  302  may also have a varied surface on an outer edge similar to rotator  202 , e.g., knurled, grooved, bumpy, machined, coated with a slip-resistant coating, etc. to improve grip when passing over obstacles. 
         [0023]    In some embodiments, portions of bash guards  200 ,  300  may be integral with components of the drive train. For example, retainer  204 ,  304  may be integral with at least one of sprocket  106  or other component of bicycle  100 . Similarly, a crankset may be provided with sprockets  106  and bash guard  200   300  in place as a single unit for mounting on bicycle  100 . In other embodiments, bash guard  200   300  may vary in size depending on the level of protection desired and on the diameter or the largest sprocket  106  of the crackset. For example, some individuals may want very little size increase of bash guard  200  over the outer diameter of the crackset to allow for maximum clearance during riding, while other individuals may want a larger rotator  202  to more fully protect the drive train. In some embodiments, rotator  202  may be supported by bearings, such as roller bearings or any other type of bearing known to those of ordinary skill. 
         [0024]    Other embodiments may include other specific forms without departing from the spirit or essential characteristics of the invention, i.e. the independent movement of a bash ring or bash rings. The described and illustrated embodiments are to be considered in all respects only as illustrative and not restrictive. For example, although some of the Figures include specific dimensions, the invention is not limited to any specific dimensions, and may be any size, thickness, weight, etc. as desired by one of ordinary skill in the art. 
         [0025]    Having described the preferred aspects, it is understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description, as many apparent variations thereof are possible without departing from the spirit or scope thereof.