Abstract:
A new aerodynamic cover for a bicycle shoe and clipless bicycle pedal for improving speed when cycling. The aerodynamic cover has a main body including an ankle portion having a rear side, a heel portion connected to the ankle portion, and a sole portion connected to the heel portion and having an underside. An opening is formed in the sole portion for allowing a bicycle pedal to be engaged to the bicycle cleat. An outwardly extending fin stretches from the rear side of the ankle portion, around the heel portion, to the underside of the sole portion. The aerodynamic cover may further have a pedal layer, a cleat layer, and a base plate layer. A gap is defined between the pedal layer and the cleat layer. The gap inhibits excessive friction between the pedal layer and the cleat layer as the cleat is pivoted with respect to the pedal.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to bicycle shoe covers and pedal covers and, more particularly, to a bicycle shoe cover and pedal cover that are aerodynamically optimized for bicycle racing. 
     Shoes and pedals play an important role in the aerodynamics of bicycle racing. During the top half of a pedal stroke, both the shoe and pedal travel into the wind faster than the rest of the bicycle frame and rider. Thus, improving the aerodynamics of shoes and pedals is particularly valuable in terms of reducing wind drag and optimizing speed. 
     In the past, lycra shoe covers have been designed to improve the aerodynamics of bicycle shoes. An example is the Pearl Izumi Aero Lycra Shoe Cover, sold by Pearl Izumi USA, Inc. of Louisville, Colo. The lycra material is lightweight and breathable, and can be stretched to fit snugly over a bicycle shoe. A zipper closure secures the shoe cover in place. Although such shoe covers improve the aerodynamics of bicycle shoes, the aerodynamics are still less than optimal. 
     In the past, clipless pedal/cleat assemblies have been designed that allow the bicyclist to pivot a shoe cleat with respect to a bicycle pedal so that the cleat can be easily engaged to and disengaged from the pedal. These pedal/cleat assemblies have lacked an aerodynamic cover optimized for bicycle racing. For example, U.S. Pat. No. 6,494,117 to Bryne discloses a clipless pedal/cleat assembly having a float range that is easily and precisely adjusted. Although the pedal/cleat assembly disclosed in this patent is lightweight and presents only a small forward profile, the aerodynamics of this pedal/cleat assembly could be improved with an appropriate cover. 
     It should be appreciated from the foregoing description that there is a need for an aerodynamic cover for a bicycle shoe and clipless pedal/cleat assembly that is optimized for bicycle racing. Specifically, there is a need for an aerodynamic cover that minimizes wind drag while not interfering with the ease with the cleat assembly can be engaged to and disengaged from the bicycle pedal. The present invention satisfies these needs and provides further related advantages. 
     SUMMARY OF THE INVENTION 
     The present invention is embodied in a new aerodynamic cover for a bicycle shoe and clipless bicycle pedal for improving speed when cycling. The aerodynamic cover comprises a main body including an ankle portion having a rear side, a heel portion connected to the ankle portion, and a sole portion connected to the heel portion and having an underside. An opening is formed in the sole portion for allowing a bicycle pedal to be engaged to the bicycle cleat. An outwardly extending fin stretches from the rear side of the ankle portion, around the heel portion, to the underside of the sole portion. 
     More particularly, the sole portion generally defines a plane. The fin is generally symmetrical about an axis that extends through the heel portion at an angle of approximately 30 degrees to approximately 40 degrees, are preferably at an angle of approximately 35 degrees, with respect to the plane of the sole portion. Dimples are formed on an outside surface of the main body for reducing drag. 
     In other, more detailed features of the invention, the main body further includes a cleat cover portion aligned with the opening formed in the sole portion and configured to receive a bicycle cleat. The rear portion of the cleat cover portion can be connected to a front portion of the fin or be spaced from the fin. 
     More particularly, the cleat cover portion has a substantially planar bottom surface, a substantially planar top surface spaced in a substantially parallel relationship with the bottom surface of the cleat cover portion, and an opening extending from the bottom surface of the cleat cover portion to the top surface of the cleat cover portion and configured to receive the cleat. The cleat cover portion can be attached to the sole portion or can be a separate piece from the remainder of the aerodynamic cover. The bottom surface of the cleat cover portion covers a smaller area than the top surface of the cleat cover portion. 
     In one embodiment, the bicycle cleat is configured to releasably engage a clipless bicycle pedal. The cleat comprises a spring housing, a bottom plate configured to be secured to the spring housing, and a spring clip mounted between the spring housing and the bottom plate. The spring housing and bottom plate define an opening sized and shaped to receive a top portion of the clipless bicycle pedal. 
     In other, more detailed features of the invention, the aerodynamic cover further comprises a pedal cover having a rounded bottom surface, a substantially planar top surface, and a recess defined in the top surface of the pedal cover and configured to receive a bottom portion of a bicycle pedal. A gap is defined between the pedal cover and the cleat cover portion when the bottom portion of the bicycle pedal has been received in the recess defined in the top surface of the pedal cover, a cleat has been received in the opening extending from the bottom surface of the cleat cover portion to the top surface of the cleat cover portion, and the cleat has engaged the bicycle pedal. The gap inhibits excessive friction between the pedal cover and the cleat cover portion as the cleat is pivoted with respect to the pedal. In one embodiment, there is less than or equal to approximately 2 Newton meters of rotational torque resistance between the pedal cover and the cleat cover portion as the cleat is pivoted with respect to the pedal. 
     In one embodiment, the recess defined in the top surface of the pedal cover extends to a side of the pedal cover, creating an indentation configured to receive a bottom portion of a bicycle pedal spindle. A plurality of tabs extend into the recess and are configured to engage the clipless bicycle pedal. A plurality of projections extend longitudinally in the recess for assisting in properly aligning the pedal cover with the clipless bicycle pedal. Dimples are formed on an outside surface of the pedal cover for reducing drag. 
     In one embodiment, the aerodynamic cover further comprises a base plate cover. The base plate cover has a substantially planar bottom surface, a top surface that substantially conforms to the bottom surface of the shoe, and an opening extending from the bottom surface of the base plate cover to the top surface of the base plate cover and configured to receive a base plate. The bottom surface of the base plate cover covers a smaller area than the top surface of the base plate cover. The base plate is configured to be attached to a cleat and follow the contour of a bottom surface of a shoe sole. 
     Other features and advantages of the present invention should become apparent from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a right-side elevation view of a right-foot aerodynamic bicycle shoe cover and pedal cover in accordance with an embodiment of the present invention. 
         FIG. 2  is a perspective view of the shoe cover and pedal cover of  FIG. 1 . 
         FIG. 3  is a perspective view of a bicycle cleat and the sole portion, cleat cover portion, and toe portion of the shoe cover of  FIG. 1 , with the cleat detached from a bicycle pedal. 
         FIG. 4  is a perspective view of the cleat of  FIG. 3 , the cleat cover portion of the shoe cover of  FIG. 1 , and a base plate cover positioned on the underside of a shoe sole, with the remaining portions of the shoe cover removed to show the shoe sole and the details of the cleat, cleat cover portion, and base plate cover. 
         FIG. 5  is a perspective view of the base plate cover of  FIG. 5  and a base plate positioned on the underside of a shoe sole. 
         FIG. 6A  is a perspective view of the pedal cover of  FIG. 1  and a bicycle pedal, with the pedal cover detached from the pedal. 
         FIG. 6B  is a cross-sectional view of the pedal cover of  FIG. 1  and the pedal of  FIG. 6A , with the pedal cover attached to the pedal. 
         FIG. 7  is a perspective view of the pedal cover and portions of the shoe cover of  FIG. 1 , with a pedal spindle protruding from the pedal cover. 
         FIG. 8  is a perspective view of the pedal cover of  FIG. 1 , the cleat cover portion of the shoe cover of  FIG. 1 , and the base plate cover of  FIG. 5  positioned on the underside of a shoe sole, with the remaining portions of the shoe cover removed to show the shoe sole and the details of the cleat cover portion and base plate cover. 
         FIG. 9  is a right-side elevation view of the pedal cover and portions of the shoe cover of  FIG. 1 . 
         FIG. 10  is a right-side elevation view of the pedal cover of  FIG. 1 , the cleat cover portion of the shoe cover of  FIG. 1 , and the base plate cover of  FIG. 5  positioned on the underside of a shoe sole, with the remaining portions of the shoe cover removed to show the shoe sole and the details of the cleat cover portion and base plate cover. 
         FIG. 11  is a front elevation view of the pedal cover and portions of the shoe cover of  FIG. 1 , with a pedal spindle protruding from the pedal cover. 
         FIG. 12  is a front elevation view of the pedal cover of  FIG. 1 , the cleat cover portion of the shoe cover of  FIG. 1 , and the base plate cover of  FIG. 5  positioned on the underside of a shoe sole, with the remaining portions of the shoe cover removed to show the shoe sole and the details of the cleat cover portion and base plate cover. 
         FIG. 13  is a bottom plan view of the pedal cover and portions of the shoe cover of  FIG. 1 , with a pedal spindle protruding from the pedal cover. 
         FIG. 14  is a bottom plan view of the pedal cover of  FIG. 1 , the cleat cover portion of the shoe cover of  FIG. 1 , and the base plate cover of  FIG. 5  positioned on the underside of a shoe sole, with the remaining portions of the shoe cover removed to show the shoe sole and the details of the cleat cover portion and base plate cover. 
         FIG. 15  is a detail view of a portion of the shoe cover of  FIG. 1 , showing dimples formed in the shoe cover. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 and 2 , there is shown a right-foot aerodynamic bicycle shoe cover  10  and pedal cover  12  in accordance with an embodiment of the present invention. The particular covers shown are configured for a right bicycle shoe and pedal, but it will be appreciated that similar covers could be oppositely configured for a left bicycle shoe and pedal. 
     The shoe cover  10  comprises an ankle portion  14 , a heel portion  16 , a sole portion  18 , a cleat cover portion  20  (see  FIGS. 3 and 4 ), a toe portion  22 , a top portion  24 , a fin  26 , and a mechanical closure  28 . The fin extends down from the rear side of the ankle portion, around the heel portion, to the underside of the sole portion. The fin is thickest at its innermost portions, where it connects with the ankle portion, heel portion, and sole portion, and thinnest at its outermost portions. In one embodiment, the fin is generally symmetrical about an axis A that extends through the heel portion at an angle of approximately 30 degrees to approximately 40 degrees, and preferably at an angle of approximately 35 degrees, with respect to the general plane of the sole portion. The fin can be formed of a lightweight material, such as closed-cell foam, covered by an aerodynamic material, such as plasticized or rubberized lycra. The fin improves the aerodynamics of the shoe cover, lessening air turbulence behind the shoe cover at it moves through the air. By giving the shoe cover a more streamlined shape, the fin reduces drag caused by a low pressure region created at the rear of the shoe cover. 
     The mechanical closure  28  secures the shoe cover  10  in place over the shoe. The mechanical closure may comprise a zipper, hook-and-loop fastener, snaps, or other closure device. In one embodiment, the mechanical closure is part of the fin  26 . In this embodiment, the fin is divided into a left part and a right part that can be snapped, zipped, or otherwise fastened together. 
     With reference now to  FIG. 3 , there is shown a bicycle cleat  30  and the sole portion  18 , cleat cover portion  20 , and toe portion  22  of the shoe cover  10  in accordance with an embodiment of the present invention, with the cleat detached from a bicycle pedal. As shown in  FIG. 3 , an opening is formed in the cleat cover portion to accommodate the cleat and allow the cleat to be engaged to a bicycle pedal. 
     In one embodiment, the cleat cover portion  20  is integral to the remainder of the shoe cover  10 . The cleat cover portion can be formed of a lightweight material, such as closed-cell foam, and bonded to the aerodynamic material that comprises the sole portion  18 . The rear end of the cleat cover portion can be connected to or spaced from the fin  26  (shown in  FIGS. 1 and 2 ). In another embodiment, the cleat cover portion is a separate piece from the remainder of the shoe cover, in which case the sole portion can be configured to fit snugly over the rounded edge of the cleat cover. 
     With reference now to  FIG. 4 , there is shown the cleat  30 , the cleat cover portion  20  of the shoe cover  10 , and a base plate cover  34  positioned on the underside of a shoe sole  36  in accordance with an embodiment of the present invention, with the remaining portions of the shoe cover removed to show the shoe sole and the details of the cleat, cleat cover portion, and base plate cover. As shown, the cleat cover portion is configured to surround the cleat. It has a substantially planar bottom surface  38 , a substantially planar top surface spaced in a parallel relationship with the bottom surface, and a rounded edge  42 . The bottom surface of the cleat cover portion covers a smaller area than the top surface. The top surface of the cleat cover portion is sized and shaped to conform substantially to the size and shape of the bottom surface  44  of the base plate cover (see  FIG. 5 ). The opening formed in the cleat cover portion extends from the bottom surface of the cleat cover portion to the top surface and is configured to receive the cleat. An indentation  46  is defined in the rounded edge  42 , proximate to the center of the left side of the cleat cover portion and is configured to accommodate the top of the spindle  48  of a bicycle pedal  50  (see  FIG. 8 ). 
     In one embodiment, as shown in  FIG. 3 , the aerodynamic material that comprises the sole portion  18  of the shoe cover  10  covers the entirety of the rounded edge  42  of the cleat cover portion  20  and is bonded thereto. The aerodynamic material thus is shaped by the rounded edge. 
     A variety of cleats compatible with a clipless pedal system may be used with the present invention. The particular cleat  30  shown in  FIGS. 3 and 4  includes a plastic spring housing  52  and a steel bottom plate  54  configured to be secured, together, by four screws  56  to a plastic base plate  58 . The spring housing and bottom plate, together, define a circular central opening  60  sized and shaped to conformably receive the pedal  50 . A single horseshoe-shaped spring clip  62  is mounted between the spring housing and the bottom plate, for releasably engaging the pedal when the cleat is positioned over the pedal. Further details about this particular cleat are disclosed in U.S. Patent Application Publication No. 2008/0110294 to Richard M. Bryne, which is incorporated herein by reference. Although the particular cleat shown has a central opening sized and shaped to receive a pedal, the present invention is compatible with a clipless pedal system wherein the cleat has a projection sized and shaped to be conformably received within a corresponding opening in a pedal. 
     With reference now to  FIG. 5 , there is shown the base plate cover  34  and base plate  58  positioned on the underside of the shoe sole  36  in accordance with an embodiment of the present invention. The base plate cover is configured to surround the base plate, to which the cleat  30  is configured to be attached. The base plate cover has a substantially planar bottom surface  44 , a top surface that substantially conforms to the shape of the underside of the shoe sole, and a rounded edge  66 . The bottom surface of the base plate cover covers a smaller area than the top surface. An opening is defined in the base plate cover, extending from the bottom surface to the top surface and configured to receive the base plate. 
     The base plate  58  itself is configured to be secured to the shoe sole  36  by screws  70  extending through three elongated openings  72  in the base plate. The base plate may be secured to a raised portion  73  of the shoe sole. Further details about this particular base plate are disclosed in U.S. Patent Application Publication No. 2008/0110294 to Richard M. Bryne. The present invention is also compatible with a clipless pedal system wherein the cleat is positioned on the underside of the shoe sole without a base plate. 
     With reference now to  FIGS. 6A and 6B , there is shown the pedal cover  12  and the pedal  50  in accordance with an embodiment of the present invention. The pedal cover is configured to be removably attached to the bottom of the pedal  50 . It has a rounded bottom surface  74  and a substantially planar top surface  75  having a recess  76  therein. The top surface of the pedal cover is sized and shaped to conform substantially to the size and shape of the bottom surface  38  of the cleat cover portion  20  of the shoe cover  10 . The recess is configured to receive the pedal and extends to the left side of the pedal cover, creating an indentation  77  in the left side that is configured to receive the bottom of the spindle  48  of the pedal. The pedal cover is attached to the pedal by means of a pair of identical, opposing side tabs  78  configured to engage a pair of identical, opposing indentations  79  in the pedal. Four longitudinally extending projections  80  engage four longitudinally extending grooves  81  in the pedal to keep the pedal cover correctly positioned with respect to the pedal. 
     With reference now to  FIGS. 7-14 , there are shown various views of the pedal cover  12  and portions of the shoe cover  10  in accordance with an embodiment of the present invention, with the pedal cover in place beneath the shoe cover. In  FIGS. 8 ,  10 ,  12  and  14 , portions of the shoe cover are removed to show the shoe sole  36  and the details of the base plate cover  34  and cleat cover portion  20  of the shoe cover. The combination of the pedal cover  12 , cleat cover portion  20 , and base plate cover  34  has a general teardrop shape to minimize drag. 
     A small gap  82  is defined between the pedal cover  12  and the cleat cover portion  20  of the shoe cover  10  when the pedal  50  has been received in the pedal cover, the cleat  30  has been received in the cleat cover portion, and the cleat has engaged the pedal. The gap assists a bicyclist in pivoting the cleat with respect to the pedal so that the cleat can be engaged to and disengaged from the pedal. The gap reduces rubbing between the pedal cover and cleat cover portion as the bicyclist pivots the cleat, thus minimizing the possibility that the shoe cover and pedal cover might interfere with the process of engaging the cleat to and disengaging the cleat from the pedal. In one embodiment, there is less than or equal to approximately 2 Newton meters of rotational torque resistance between the pedal cover and the cleat cover portion as the cleat is pivoted with respect to the pedal. 
     With reference now to  FIG. 15 , there is shown a detail view of a portion of the shoe cover  10 , showing dimples  84  formed in the cover. The dimples reduce drag, similar to the way dimples on a golf ball reduce drag. 
     Although the invention has been described in detail with reference only to the presently preferred embodiments, those skilled in the art will appreciate that various modifications can be made without departing from the invention. Accordingly, the invention is defined only by the following claims.