Abstract:
A frame-supported vehicle, such as a bicycle or the like, has at least one frame component made of a light diffusing or fluorescent translucent or transparent material to form a leaky light pipe, and at least one light source in light communication with the frame component, whereby light propagates within the frame and is visible from outside the frame by diffusion or fluorescence or a combination thereof. The bicycle is highly visible at night, and may carry logos or other indicia that are enhanced by the background illumination, which may be redirected out of the tube. The frame component may be load bearing or non load bearing. In the latter case, it may be provided as an add-on accessory.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation-in-part of U.S. patent application Ser. No. 13/096,241 filed Nov. 1, 2012. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to frame-supported vehicles with high visibility. Such frame-supported vehicles include bi-cycles, tri-cycles, scooters and other like vehicles. 
       BACKGROUND OF THE INVENTION 
       [0003]    When riding a bicycle or like vehicle in conditions of low light or diminished visibility, it is desirable to increase ability for other vehicles and pedestrians to detect the bicycle and hence protect the rider from accidental impact. Currently there exist a variety of aftermarket lighting systems designed to project light away from the bike. 
         [0004]    Current lighting systems on the market generate narrow light beams projected or reflected away from the bicycle. These options are directional in nature and have limited ability to increase the rider&#39;s visibility. The light is projected away from the bike, rather than illuminating the bicycle itself. 
         [0005]    U.S. Pat. Nos. 5,823, 653 and 6,779,913 disclose lights that are affixed to the bicycle frame. US patent application no. 2009/0080207 discloses the use of lights that can be incorporated within a translucent frame. 
         [0006]    In these systems, however, the light sources are visible through the translucent frame, and do not give an even illumination. 
       SUMMARY OF THE INVENTION 
       [0007]    According to the present invention there is provided frame-supported vehicle comprising at least one frame component made of a material forming a leaky light pipe, and at least one light source for launching light into the leaky light pipe, whereby the light from the light source propagates within the light pipe and is externally visible. The expression “externally visible” means that the light is visible by an observer at a distance from the bicycle. The light itself of course propagates internally within the bicycle frame. 
         [0008]    The leaky light pipe may be load bearing or non-load bearing. If it load-bearing it may include a reinforcing rod, for example, of steel for added strength. If non load-bearing it may be in the form of an accessory that can be clipped onto the vehicle frame. 
         [0009]    In one embodiment the frame-supported vehicle is a bicycle, but it may also be a tri-cycle, scooter, and other like vehicle that is based on a frame structure. 
         [0010]    Light propagates within the light pipe, but unlike an optical fiber, for example, the light pipe is deliberately designed to be “leaky” so that the light propagating within it is externally visible. It will be understood that the light pipe can be in the form of a tube or a rigid rod. 
         [0011]    Thus, in accordance with an embodiment of the present invention the bicycle frame, or part thereof, is made of a transparent or translucent light diffusing material illuminated by a source located at one or both ends and arranged such that light propagates within the walls of the frame and is diffused by the material over a wide area. 
         [0012]    The invention actually causes the bicycle, to become illuminated, rather than simply projecting light away from the bicycle and rider. 
         [0013]    Embodiments of the present invention generally take the form of a molded or fabricated bicycle frame manufactured from transparent or translucent polymers. The frame is then fitted with a series of lighting elements, which project light into the end of the frame structure such that it propagates along the wall of the frame. Due to the light transmission capability of the frame materials, some or all the major frame sections can be illuminated in this method so that the major part of the bicycle becomes luminescent. 
         [0014]    The frame structure propagates the light along its length within the material of the structure, which can be in the form of a rod or tube. 
         [0015]    In another aspect the invention comprises a frame structure for a frame-supported vehicle comprising at least one rod or tube made of a material forming a leaky light pipe, and at least one light source for launching light into the leaky light pipe, whereby the light from the light source propagates within the light pipe and is externally visible. 
         [0016]    The frame structure may be molded as an integral unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The invention will now be described in more detail, by way of example only, with reference to the accompanying drawings, in which: 
           [0018]      FIG. 1  is a side elevation including an illuminate system in accordance with one embodiment of the invention; 
           [0019]      FIG. 2  is a diagrammatic side view of a frame component with a solid light pipe; 
           [0020]      FIG. 3  is an end view of the frame component; 
           [0021]      FIG. 4  shows a detail of  FIG. 2 ; 
           [0022]      FIG. 5  shows an embodiment where the frame component is in the form of a hollow tube; 
           [0023]      FIG. 6  is a perspective view of a molded unitary frame in accordance with an embodiment of the invention; and 
           [0024]      FIG. 7  is a sectional view of the molded frame; 
           [0025]      FIGS. 8   a  to  8   d  show respectively a side view, bottom view top view and sectional view of the frame; 
           [0026]      FIGS. 9   a  to  9   c  show respectively a plan view, side view, and end view of an insert; 
           [0027]      FIGS. 10   a  to  10   c  show respectively a perspective view, a plan view, and an end view of a frame including an insert; and 
           [0028]      FIG. 11  is a perspective view of an add-on light pipe. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]      FIG. 1  shows a prototype that has been constructed using fabricated sections of rod, which are joined by steel intersection points taken from a commercial bike frame. Major frame components  1  and  2  have been replaced by polycarbonate rods. Each polycarbonate rod forms a light pipe with LED lighting elements (not shown in  FIG. 1 ) mounted at each end for launching light into the light pipe. 
         [0030]    The lighting elements are designated  3  in  FIG. 2 , which shows a frame component  1  made of a solid rod as employed in  FIG. 1 , with the lighting elements mounted at each end. The lighting elements  3  are set in recesses  3   a  in the ends of the solid rod. 
         [0031]    The lighting elements  3  are powered either via battery  5  or bicycle tire generator (not shown). A switch  4  can be provided for turning the lighting elements on and off. This can be mounted on the handlebars if desired. In the embodiment shown in  FIG. 1 , there are four lighting elements and four switches, one at each end of each rod, but of course it will be appreciated that the lighting elements can be connected to a common switch. 
         [0032]    The light elements can conveniently be recessed into cavities at the end of the frame components. 
         [0033]    As shown in  FIG. 2 , light rays  6  propagate within the solid light pipe partly by total internal reflection, in much the same manner as an optical fiber, except unlike an optical fiber the light pipe is designed to be leaky so that light rays  8  leak out of the rod in part due to the diffusive properties of the material. Also, because of the large diameter of the rod as compared to an optical fiber, not all the rays will strike the walls at an angle above the critical angle, and these rays, such as ray  13 , will also leak out due to refraction at the frame air interface. This gives the frame component illuminated at one end a luminescent appearance similar to a toy lightsaber. Such a structure can be generally considered as a leaky light pipe. 
         [0034]    The diffusion properties can be enhanced if necessary by including small beads of glass or other polymer of different refractive index, for example nanoparticles, in the frame members to increase the light diffusing properties of the material. 
         [0035]    The frame components  1 ,  2  can be manufactured with various textures and etchings  9 , shown in more detail in  FIG. 4 . These etchings have facets  10  which will refract the light out and illuminate the bicycle in various decorative designs. As the light strikes the facets, light that would otherwise be above the critical angle will be at an angle of incidence less than the critical angle for total internal reflection and thus emerge through the facet. This effect will give the facet, and hence the associated etching or engraving, the appearance of being illuminated against the background of the luminescent frame. The rays that would have struck the walls below the critical angle will also of course still be refracted out. 
         [0036]    The frame components  1 ,  2 , can be made from similar polymeric or other materials to polycarbonate that have light diffusing properties. They can be in the form of hollow tubes or solid rods. 
         [0037]      FIG. 5  shows an embodiment where the frame component is in the form of a hollow tube. In this case, the light will propagate within the walls of the tube, and as more rays will strike the boundary at an angle above the critical angle, less light will leak than in the case of the rigid rod shown in  FIG. 2 . While the light sources are typically LEDs, other sources could be used if desired. 
         [0038]    Also, while the light sources are preferably installed at the ends of the structures, they could also be installed at other locations where the light will be launched directly into the frame components for propagation along their length. However, the light sources will not normally be externally visible along the entire length of the frame component. 
         [0039]    Thus, in accordance with embodiments of the invention, light from these sources is directed into the tubes, diffusing along its path to light the entire frame section. 
         [0040]    It is also possible to include fluorescent material within the molded frame to enhance the luminescent effect. One possibility would be to use UV LEDs with fluorescent material mixed embedded or mixed with the polycarbonate frame. 
         [0041]    The embodiment shown in  FIGS. 6 ,  7  and  8   a - 8   d  comprises a molded polycarbonate frame member having the major sections  20 ,  23 , and  24  made in one piece. The sections  20  and  23  can be solid, whereas the section  24  can have a hollow end to receive a supporting post of a saddle. The forward section of the frame member has a vertical bore receiving a steel bushing  25  for the front frame member supporting the front wheel. The rear junction of the sections  23 ,  24  has a bore receiving a steel bushing  26  for the receiving the bicycle cranks. 
         [0042]    LED lighting elements  27 ,  28 ,  29 ,  30  are recessed into the ends of the frame members  20 ,  23 , causing these members to become luminescent as explained with reference to  FIG. 2 , The LED lighting elements can be in the form of an array of LEDs, or a single high intensity LED. 
         [0043]    A battery is inserted in recess  31  with a snap fit cover. A switch can be provided (not shown). This battery can power the rear end lights  27 ,  30 . Likewise a battery can be fitted into recess  40  in the end of the frame also fitted with a snap cover to power the front end LEDs  28 ,  29 . The recesses can be closed by covers once the components have been installed, The wiring can be external or incorporated into channels in the frame members during the molding process. As the current is very small, only very fine wires are required, although in one example ¼″ channels were provided to accommodate the wires. 
         [0044]    For marketing purposes, patterns can be engraved into the frame sections including sports team logos, corporate logos, cartoon characters, skulls, and the like for marketing purposes. These will then appear bright, being illuminated by refracting the internal light that is transmitted along the frame members. 
         [0045]    Unlike the prior art systems, the light sources need not be visible, yet the illuminated frame has a luminescent quality that makes it highly visible. 
         [0046]    In the described embodiments, it is envisaged that the frame component made of material forming the leaky light pipe form part of the load-bearing structure of the bicycle. However, it will be appreciated that it is also possible to incorporate a leaky light pipe as described either as a non loadbearing frame component, such as a projecting piece, or also as an add-on part to an existing frame. For example, as shown in  FIG. 11  a hollow resilient tube  50  constituting a cylindrical light pipe could be clipped on to the outside of one of the load-bearing frame components, such the sections  20 ,  23 ,  24 , by prying apart the edges  51   a ,  51   b  of the slit  51 . For this purpose, an axial slit  51  could be provided in along the length of the tube to allow it to be opened and clipped around the load-bearing frame section  23 . In this case the wall  54  of the tube  50  acts as the leaky light pipe. Radial recesses  54  in the wall of the tube could accommodate LEDs  55  and batteries  56 , or alternatively the tube  53  could be provided with contacts or wires for connection to an external power source mounted on the bicycle frame. 
         [0047]    The leaky light pipe may also be configured to direct light in a specific direction, for example, toward the rider. 
         [0048]    In certain applications, such as for adult riders but also for younger riders, such as for 16″ frames, it may be desirable to strengthen the polycarbonate frame. This can be achieved by molding the polycarbonate or polymeric frame around an insert, which is this example is made of steel, although it will be understood that other suitable strengthening materials can be employed. The steel insert, as shown in  FIGS. 9   a - 9   c , is of unitary construction, and comprises a connecting rod  40  integral with the front bushing  25  and rear bushing  24 . The rod  40  is embedded in the lower angled frame section  23  connecting the front and rear portions of the frame as shown in  FIGS. 10   a  to  10   c.