Abstract:
Skateboards methods of riding and steering a foldable skateboard with two large front wheels pivotally attached to the skateboard and a single large rear centered wheel with depressible brake. The skateboard allows for the rider with one foot on the skateboard to propel the skateboard by pushing off the ground with another foot. A stabilizer with angled bolt/pin/rod that inserts into an oblong eyelet opening with pliable bushing on the front axle can allow the rider to tilt the board with their weight to turn to the left or to the right. A folding mechanism having brackets with parallel plates and an end hingedly attached to outer ends of a front frame rear frame members. Opposite end of the brackets can have holes that align with holes in the front frame member where a removable pin locks the front and rear frame members in an unfolded position.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This invention is a Continuation In Part of U.S. patent application Ser. No. 13/482,600 filed May 29, 2012, which claims the benefit of priority to U.S. Provisional Application Ser. No. 61/631,689 filed Jan. 9, 2012. 
    
    
     FIELD OF INVENTION 
     This invention relates to skateboards, and in particular to skateboard devices, and methods of riding and steering an elongated foldable skateboard with two large front wheels and a single large rear centered wheel with depressible brake, so that the rider with one foot on the skateboard can propel the skateboard by pushing off the ground with another foot. 
     BACKGROUND AND PRIOR ART 
     Conventional skateboards generally use four small diameter wheels positioned beneath the board on which the rider stands. The wheels are made of a solid material that provides no shock absorption. The board is propelled by the rider by kicking one foot on the ground. Steering is accomplished by shifting the rider&#39;s weight to tilt the board. The limitation of this version is that the small diameter wheels can only be used on smooth surfaces that are free of debris. 
     New types of skateboards have been proposed over the years to overcome the limitations of the small wheels by creating skateboards with large diameter wheels and pneumatic tires. However, these boards cannot be easily propelled by the rider. The large wheel boards have higher riding platforms which makes the boards unstable, difficult to ride, and potentially unsafe to the rider. Most of these other types of boards are propelled only by gravity and thus require a sloping surface to be used. 
     U.S. Pat. No. 6,398,237 to Attey describes a skateboard that utilizes two in-line large diameter wheels where a single front wheel pivots to accommodate steering. Similar to a bicycle, with only two wheels this device can only remain vertical while in motion. A rider would not be able to remove one foot from the device for propulsion without losing stability and falling off the board. 
     U.S. Pat. No. 5,794,955 to Flynn describes a mountain board that requires four large diameter wheels which are mounted on wide axles that extend beyond the width of the board. The two wheels at the rear of the board can cause interference for the rider should the rider attempt to propel the board by kicking one foot. 
     U.S. Pat. No. 5,100,161 to Tillyer; U.S. Pat. No. 5,997,018 to Lee; U.S. Pat. No. 5,645,291 to Ramage; and U.S. Pat. No. 5,474,314 to Lehman also each require four large wheels located beneath the board that results in a high riding platform, or ‘deck,’ which makes these devices cumbersome and difficult to operate. 
     U.S. Pat. No. 5,551,717 to Milne has two front wheels that steer and a single rear wheel; however, this device is much less stable. Milne&#39;s device includes a deck that is mounted to the frame via longitudinal pivot points beneath the deck. This allows the deck to tilt from side to side while the frame remains level. Steering linkage components connected to the deck turn the front wheels when the deck is tilted. The deck is higher than the axles of the wheels. The combination of the high deck and the pivot point located below the plane in which the rider stands can make this device unstable. Additionally, the Milne&#39;s device appears to be limited for off-road use only and may further be limited to use on sloping surfaces. 
     Thus, the need exists for solutions to the above problems with the prior art. 
     SUMMARY OF THE INVENTION 
     A primary objective of the present invention is to provide skateboard devices, and methods of riding and steering an elongated steerable and foldable skateboard with two large front wheels and a single large rear centered wheel that can be ridden on a variety of terrain surfaces. 
     A secondary objective of the present invention is to provide skateboard devices, and methods of riding and steering an elongated steerable and foldable skateboard with two large front wheels and a single large rear centered wheel, where the wheels can have shock absorption effects. 
     The steerable and foldable skateboard invention can be ridden on a variety of terrain and can also be propelled by the rider. The invention is not limited to off-road use only as it can be used on a variety of uneven paved surfaces like asphalt even if the riding surface is level. 
     An embodiment of the board is to have three wheels which create a stable platform having two wheels in the front and one wheel medially disposed in the rear. The single rear wheel can provide clearance for the rider&#39;s foot so the rider can propel the board by kicking along the ground. 
     The wheels are generally of a large diameter to allow the board to travel on irregular surfaces. The wheels can have pneumatic tires to provide shock absorption. In practice it has been found the preferred wheel diameters are in the approximately 30 cm to approximately 60 cm range. 
     Two front wheels on the board can be pivotally connected to the frame to allow the wheels to turn and steer the board. The two front wheels can either be fixed to a common axle with a single pivot point centered about the axle or they can be mounted with a separate pivot point for each front wheel for a total of two pivot points. 
     From experience it has been found that when the pivot point or points are angled forward between approximately 10 degrees to approximately 45 degrees off vertical it causes the front wheels to turn when the riding platform is tilted left or right. 
     It has also been found that if a single pivot point is used to turn the front wheels it is best this pivot point lies in the same plane as the riding surface for more accurate responsiveness. 
     The axle track of the two front wheels can be narrow to keep the device compact, lightweight, and maneuverable. This width must increase as the diameter of the wheels increases as to prevent the wheels from contacting the frame while turning. The preferred width of the axle track is between approximately 30 cm and approximately 42 cm. 
     A frame supporting a riding platform can be positioned between the front and rear wheels. Preferably the frame will position the axles of the wheels in a plane above the plane of the riding platform which increases stability and keeps the riding platform low to the ground. The height of the riding surface is comparable to that of a conventional skateboard. 
     The riding platform can be stabilized by stabilizing the pivot or pivots with material, such as but not limited to rubber or polyurethane bushings. The overall wheelbase is preferably in the about 70 cm to about 117 cm range, and the ideal wheelbase of the device would vary based on the size of the rider. 
     The pivot and steering mechanisms can include a raised eyelet on a middle portion of the axle member, the eyelet having an enlarged opening therethrough, and a stabilizing member attached to the frame having an angled rod with an end attached into the enlarged opening in the eyelet with a pliable bushing, the enlarged opening having a larger diameter than the diameter of the rod, the opening being large enough to allow for the front wheels on the axle member with attached eyelet to move to the left and to the right without having inner edges of the opening in the eyelet from contacting the rod, wherein the stabilizing member allows for turning of the skateboard when the skateboard is tilted to the right or to the left. 
     The frame can also separate along the lateral axis which will enable the device to fold for storage. When in the unfolded position, the rear section of the frame can be inserted a short distance into the front section of the frame. The front and rear sections can be drawn together by an attached handle and lever. The handle can be permanently attached to the front section of the frame by a pivotal connection. The lever can be permanently attached to the handle by a pivotal connection, and the lever can be permanently attached to the rear section of the frame by a pivotal connection so all components remain attached when the device is folded. 
     A folding mechanism can include a front frame and rear frame having male ends and female ends which couple with each other for stability with the front frame and the rear frame being drawn together by a lever pivotally connected to both the front and rear frames that holds both the front and the rear frames together when folded and tightly draws the front and the rear frames together when unfolded. 
     The three wheel lean-steer skateboard can accept attachments such as a handle that a rider can use for additional stability, or a sail that would enable the rider to be propelled by the wind. 
     The three wheel lean-steer skateboard is well suited to being modified to be powered by a motor, either gas or magnetic, which can drive the single rear wheel. 
     Further objects and advantages of this invention will be apparent from the following detailed description of the presently preferred embodiments which are illustrated schematically in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is an exploded upper perspective view of the steerable and foldable skateboard. 
         FIG. 1A  is an enlarged exploded upper perspective view of the steering mechanism of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 1B  is an enlarged upper perspective view of the steering mechanism of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 2  is an assembled upper perspective view of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 3  is a front view of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 4  is a rear view of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 5  is a left side view of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 6  is a top view of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 7  is a bottom view of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 8  is an enlarged top view of the steering mechanism of the skateboard of  FIG. 1 . 
         FIG. 9  is a top view of the steerable and foldable skateboard of  FIG. 1  showing front steerable wheels. 
         FIG. 10  is an enlarged bottom perspective view of the folding mechanism of steerable and foldable skateboard of  FIG. 1  with the skateboard in an unfolded position. 
         FIG. 11  is another enlarged bottom perspective view of the folding mechanism of the skateboard of  FIG. 1  with the skateboard in a partially folded position. 
         FIG. 12  is a side view of the skateboard of  FIG. 1  with partially folded mechanism of  FIG. 11  with skateboard in a partially folded position. 
         FIG. 13  is a side view of the skateboard of  FIG. 1  and  FIG. 12  with the skateboard in a fully folded position. 
         FIG. 14  is an enlarged perspective view of the brake mechanism of the steerable and foldable skateboard of  FIG. 1 . 
         FIG. 15  is a perspective view of the folded skateboard of  FIG. 13  with attached lock. 
         FIG. 16  is a perspective view of a user on the skateboard of  FIG. 1 . 
         FIG. 17  is a perspective view of the steerable and foldable skateboard with an attached handle. 
         FIG. 18  is a perspective view of the steerable and foldable skateboard with an attached sail. 
         FIG. 19  is a side view of a steerable and foldable skateboard frame with another folding mechanism. 
         FIG. 20  is a perspective view of the underside of the frame of  FIG. 19 . 
         FIG. 21  is another perspective view of the underside of the frame of  FIG. 20 . 
         FIG. 22  is a perspective view of only the folding mechanism of  FIGS. 19-21 . 
         FIG. 23  is another perspective view of the folding mechanism if  FIG. 22  partially folded. 
         FIG. 24  is another perspective view of the folding mechanism of  FIG. 22  fully folded. 
         FIG. 25  is a side view of the folding mechanism of  FIG. 24  fully folded. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Before explaining the disclosed embodiments of the present invention in detail it is to be understood that the invention is not limited in its applications to the details of the particular arrangements shown since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation. 
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 A list of components will now be described. 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 1. 
                 foldable skateboard 
               
               
                 10. 
                 front deck 
               
               
                 12.  
                 forward end 
               
               
                 15.  
                 fastener(s) 
               
               
                 18.  
                 back end 
               
               
                 20.  
                 rear deck 
               
               
                 22.  
                 forward end 
               
               
                 25.  
                 fastener(s) 
               
               
                 28.  
                 back end 
               
               
                 30.  
                 U-shaped front frame 
               
               
                 31.  
                 holes for pin(350) 
               
               
                 32.  
                 left elongated member 
               
               
                 34.  
                 apex end 
               
               
                 35.  
                 cross brace(s) 
               
               
                 36.  
                 right elongated member 
               
               
                 38.  
                 pivot point 
               
               
                 39.  
                 fold-lock handle 
               
               
                 40.  
                 rear frame 
               
               
                 42.  
                 left elongated member 
               
               
                 43.  
                 pivot point 
               
               
                 44.  
                 left bent end 
               
               
                 45.  
                 cross brace(s) 
               
               
                 46.  
                 right elongated member 
               
               
                 47.  
                 rear frame dropouts 
               
               
                 48.  
                 right bent end 
               
               
                 49.  
                 fold-lock lever 
               
               
                 50.  
                 left front wheel 
               
               
                 52.  
                 tire 
               
               
                 54.  
                 rim 
               
               
                 56.  
                 spoke(s) 
               
               
                 58.  
                 center 
               
               
                 59.  
                 fastener 
               
               
                 60.  
                 main axle 
               
               
                 61.  
                 solid bushing 
               
               
                 62.  
                 left axle arm 
               
               
                 64.  
                 main axle pivot bolt/pin/rod 
               
               
                 65.  
                 bushing(s)/washer(s) 
               
               
                 66.  
                 threaded knob 
               
               
                 68.  
                 right axle arm 
               
               
                 69. 
                 metal eyelet 
               
               
                 70. 
                 right front wheel 
               
               
                 72. 
                 tire 
               
               
                 74. 
                 rim 
               
               
                 76. 
                 spoke(s) 
               
               
                 78. 
                 center 
               
               
                 79. 
                 fastener 
               
               
                 80. 
                 rear wheel 
               
               
                 82. 
                 tire 
               
               
                 84. 
                 rim 
               
               
                 86. 
                 spoke(s) 
               
               
                 88. 
                 center 
               
               
                 89. 
                 rear wheel axle 
               
               
                 90. 
                 brake pedal 
               
               
                 92. 
                 depressible member 
               
               
                 94. 
                 generally L shaped leg 
               
               
                 95. 
                 pivot point(s) 
               
               
                 96. 
                 rear frame pivot mount(s) 
               
               
                 97. 
                 pivot pin 
               
               
                 98. 
                 leg catch end 
               
               
                 99. 
                 brake cable(s) 
               
               
                 100. 
                 Pull Cable Brake, such as U-brake 
               
               
                 108.  
                 brake shoe(s) 
               
               
                 110.  
                 lock cable 
               
               
                 116.  
                 fastener(s) 
               
               
                 118.  
                 lock flange with socket 
               
               
                 130.  
                 bike rack 
               
               
                 140.  
                 rider 
               
               
                 160.  
                 handle 
               
               
                 180.  
                 sail 
               
               
                 200.  
                 stabilizing bolt assembly 
               
               
                 202.  
                 stabilizing bolt assembly mounting plate 
               
               
                 204.  
                 fastener(s) 
               
               
                 206.  
                 vertical portion of stabilizing bolt assembly 
               
               
                 208.  
                 angled portion of stabilizing bolt assembly 
               
               
                 209.  
                 stabilizing bolt 
               
               
                 300.  
                 folding mechanism with brackets and pin 
               
               
                 310. 
                 bracket 
               
               
                 320.  
                 plate 
               
               
                 321.  
                 hole 
               
               
                 322.  
                 rear end 
               
               
                 325.  
                 bottom plate 
               
               
                 330.  
                 plate 
               
               
                 331.  
                 hole 
               
               
                 332.  
                 rear end 
               
               
                 340.  
                 hinge 
               
               
                 350.  
                 quick-release pin 
               
               
                   
               
             
          
         
       
     
       FIG. 1  is an exploded upper perspective view of the novel foldable skateboard  1 .  FIG. 1A  is an enlarged exploded upper perspective view of the steering mechanism of the steerable and foldable skateboard  1  of  FIG. 1 .  FIG. 1B  is an enlarged upper perspective view of the steering mechanism of the steerable and foldable skateboard  1  of  FIG. 1 .  FIG. 2  is an assembled upper perspective view of the steerable and foldable skateboard  1  of  FIG. 1 .  FIG. 3  is a front view of the steerable and foldable skateboard  1  of  FIG. 1 .  FIG. 4  is a rear view of the steerable and foldable skateboard  1  of  FIG. 1 .  FIG. 5  is a left side view of the steerable and foldable skateboard  1  of  FIG. 1 .  FIG. 6  is a top view of the steerable and foldable skateboard  1  of  FIG. 1 .  FIG. 7  is a bottom view of the steerable and foldable skateboard  1  of  FIG. 1 . 
     Referring to  FIGS. 1-7 , the novel foldable and steerable skateboard  1  can include a front deck  10  having a forward end  12  and a back end  18  with fastener(s)  15 , such as screws, bolts and the like, that can attach the front deck  10  to the U-shaped front frame  30 . The front frame  30  can include a left elongated member  32 , apex end  34  and right elongated member  36  of the U-shaped front frame  30 . The elongated member  32 ,  36  can be stiffened by cross brace(s)  35 . Skateboard  1  can further include a rear deck  20  having a forward end  22  and a back end  28  with fastener(s)  25 , such as screws, bolts, and the like, that can attach the rear deck  20  to the rear frame  40 . The rear frame  40  can include a left elongated member  42  with left bent end  44  and right elongated member  46  with right bent end  48  which can be further stiffened by cross brace(s)  45 . 
     The height of the decks  10 ,  20  can be off the ground preferably in the approximately 6 cm to approximately 12 cm range, although it has been found the ideal height is approximately 11 cm which allows room for the pneumatic tires  52 ,  72 ,  82  to compress when the rider&#39;s weight is applied and still provide adequate ground clearance. The rear of the frame  40  will curve upward to extend to the point of the rear axle center  88  of the rear wheel  80 . 
     A pair of left and right front wheels  50 ,  70  can be attached to a front apex end  34  of the front frame  30  with a main axle  60 . Each of the front wheels  50 ,  70  can include a tire portion  52 ,  72 , attached to a circular rim  54 ,  74  that connect to a center  58 ,  78  by respective spokes  56 ,  76 . The front wheels  50 ,  70  can be attached to outer ends of bent arms  62 ,  68  of the main axle  60  by respective wheel fastener type bolts  59 ,  79 . The bent axle arms  62 ,  68  can be bent down and inward toward the middle. 
     A single rear wheel  80  can include a tire portion  82  attached to a circular rim  84  that connects to a center  88  by spokes  86 . Rear wheel  80  be attached by outwardly extending axle pin(s)  89  to rear lower facing dropouts  47  on the bent ends  44 ,  48  of the rear frame  40 , and can be held in place by typical nuts, and the like. 
     Each of the wheels  50 ,  70  and  80  can be large wheels having a diameter of approximately 30 cm to approximately 60 cm, and the tires  52 ,  72 ,  82  can be solid rubber or pneumatically filled which can have a shock absorbing effect. 
       FIG. 8  is an enlarged top view of the steering mechanism of the skateboard  1  of  FIG. 1 .  FIG. 9  is a top view of the foldable and steerable skateboard  1  of  FIG. 1  showing front steerable wheels  50 ,  70 . 
     Referring to  FIGS. 1-3 ,  6 - 9 , and  15 , the front wheels  50 ,  70  can be pivotally attached to the front frame  30 . The main axle  60  can be pivotally attached to the apex portion  34  of the front frame  30  by a bolt  64  which passes through a solid bushing  61  that is attached to the apex end of the frame  34 . The solid bushing  61  can be angled to be forward offset from the front frame  30  by an angle, which allows the arms  62 ,  68  of the axle  60  to be approximately 10 degrees to approximately 45 degrees off vertical which forces the pair of front wheels  50 ,  70  to turn when the skateboard  1  is tilted side-to-side by the rider  140  (shown in  FIG. 16 ). 
     The solid bushing  61  can be angled forward by at least 10 degrees off vertical which forces the front axle  60  to rotate when the forward and rear decks  10 ,  20  are tilted which allows the skateboard  1  to turn as shown in  FIG. 9 . The pivot point where the main axle pivot bolt  64  inserts into the solid bushing  61  lies in the same plane as the riding surface of the decks  10 ,  20 . 
     Referring to  FIGS. 1A and 1B , the main axle  60  can be stabilized by rubber or polyurethane bushings  65  mounted on either side of a metal eyelet  69  that is attached to the main axle  60 . The rubber bushings  65  can be held in place by a stabilizing bolt assembly  200  that is attached to the U-shaped front frame  30  by fasteners  204 . The stabilizing bolt assembly  200  holds the stabilizing bolt  209  which passes through the metal eyelet  69 . A turn knob  66  is threadably attached to the stabilizing bolt  209  enabling the user to adjust steering tension on the fly by tightening or loosening the knob  66  and compressing or decompressing the rubber bushings  65 . 
     Referring to  FIGS. 1A ,  1 B,  2 , and  16 , Steering is accomplished by having the main axle pivot bolt  64  permanently attached to the main axle  60  in the middle of the axle  60  protruding downward. The main axle pivot bolt  64  can be inserted into a solid metal bushing  61  that is attached to the front frame  30  and the main axle pivot bolt  64  can be secured with a nut below the bushing  61  on the bottom of the frame. This allows the main axle  60  to spin within the solid bushing  61 . The solid metal bushing  61  can be mounted on an angle leaning forward by 10 degrees to 45 degrees off vertical. By mounting the bushing  61  on a forward angle this causes the frame  30 ,  40  to tilt to the side when the main axle  60  turns. Conversely, if the frame  30 ,  40  is tilted it causes the main axle  60  to turn. 
     When the main axle  60  is perpendicular to the frame  30 ,  40 , the front wheels  50 ,  70  can be pointed straight forward and the frame  30 ,  40  is level. When the main axle  60  pivots to the right (clockwise), the frame  30 ,  40  tilts to the right. When the main axle  60  pivots to the left (counterclockwise), the frame  30 ,  40  tilts to the left. The frame  30 ,  40  must be stabilized in the level position for the rider  140  to be able to ride the skateboard  1 . The frame  30 ,  40  should only tilt when the rider  140  forces the frame  30 ,  40  to tilt in order to steer the front wheels  50 ,  70  in the direction the rider  140  wants to go. 
     To stabilize the frame  30 ,  40  in the level position, the main axle  60  must be stabilized in the straight forward position. This is accomplished by attaching a metal eyelet  69  on top of the main axle  60  directly in line with the main axle  60  and perpendicular to the frame. The metal eyelet  69  can be a flat piece of metal that contains an elliptical hole in the middle. The metal eyelet  69  is centered in the same axis in which the main axle  60  pivots, directly above the main axle pivot bolt  64 . The stabilizing bolt  209  which is attached to the front frame  30  passes through the middle of the elliptical hole in the metal eyelet  69 . The elliptical hole in the eyelet  69  can provide enough clearance around the stabilizing bolt  209  so the bolt  209  does not come in to contact with the eyelet  69  when the main axle  60  turns. 
     There can be two rubber bushings  65  that are mounted on the stabilizing bolt  209  on either side of the metal eyelet  69  sandwiching the eyelet  69  between the two bushings  65 . The rubber bushings  65  can be compressed slightly by tightening a threaded knob  66  onto the stabilizing bolt  209 . This holds the metal eyelet  69  and thus the main axle  60  in a position that is perpendicular to the frame. 
     When the main axle  60  is turned, the metal eyelet  69  must apply force against the rubber bushings  65  and the spring-like properties of the rubber bushings  65  try to resist this force. This means force must be applied to turn the main axle  60  and when that force is removed the rubber bushings  65  return the main axle  60  to the straight forward position. When tilting force is applied to the frame  30 ,  40  by the rider  140  this force transfers to the turning motion of the main axle  60  which is resisted by the rubber bushings  65 . The amount of tilting force necessary to turn the front wheels  50 ,  70  can be adjusted by the rider  140  by either tightening or loosening the threaded knob  66  and thus compressing or decompressing the rubber bushings  65  against the metal eyelet  69 . 
       FIG. 10  is an enlarged bottom perspective view of the folding mechanism of foldable skateboard  1  of  FIG. 1  with the skateboard  1  in an unfolded position.  FIG. 11  is another enlarged bottom perspective view of the folding mechanism of the foldable skateboard  1  of  FIG. 1  with the skateboard  1  in a partially folded position.  FIG. 12  is a side view of the skateboard  1  of  FIG. 1  with partially folded mechanism of  FIG. 11  with skateboard  1  in a partially folded position.  FIG. 13  is a side view of the skateboard  1  of  FIG. 1  and  FIG. 12  with the skateboard  1  in a fully folded position. 
     Referring to  FIGS. 1 ,  2 ,  5 - 7 , and  9 - 13 , the skateboard  1  can have a front deck  10  attached to a front frame  30  that can fold against a rear deck  20  attached to a rear frame  40  by separating the two frame sections  30 ,  40 . The rear frame  40  will insert into the front frame  30  by approximately 2 cm to approximately 6 cm. The fold-lock handle  39  can pivotally attach to the left and right elongated members  32 ,  36 . One end of the fold-lock lever  49  can pivotally attach to the fold-lock handle  39  while the other end can pivotally attach to the left and right elongated members of the rear frame  42 ,  46 . When the fold-lock handle  39  is laid flat against the bottom of the front deck  10  the fold-lock lever  49  is pulled forward and the front frame  30  and rear frame  40  are drawn together locking the skateboard  1  into the unfolded position as seen in  FIG. 10 . When the fold-lock handle  39  is pulled downward away from the front deck  10 , the fold-lock lever extends and pushes front frame  30  and rear frame  40  apart allowing the skateboard  1  to be folded as seen in  FIG. 11 . The fold-lock handle  39  is permanently attached to front frame  30  by two pivot points  38 . The fold-lock lever  49  is permanently attached to the fold-lock handle  39  as well as to the rear frame  40  by a pivot  43 . This allows the front frame  30  and rear frame  40  to remain attached while folding the skateboard  1 . The folded skateboard  1  allows for the unused skateboard  1  to be easily stored and/or transported. 
       FIG. 14  is an enlarged perspective view of the brake mechanism  90  of the steerable foldable skateboard  1  of  FIG. 1 . Preferably the brake pedal  90  can be suspended in the upward position by a torsion spring. As the brake pedal portion  92  is depressed, it will pull a cable  99  forward which can operate any of the various braking devices used on bicycles including cantilever brakes or a disc brake. 
     While a U brake configuration is shown, the invention can allow for using any type of pull cable brake assembly, such as but not limited to U-brake, side-pull cantilever brake, disc brake, and the like. 
     Referring to  FIGS. 1-3 ,  5 - 7 ,  9  and  12 - 14 , a generally horizontal depressible pedal  90  with a generally downwardly angled L shaped leg  94  with corner pivot point  95  therebetween pivotally attachable to rear frame pivot mounts  96  on the elongated members  42 ,  46  on the rear frame  40  by pivot pin  97 . Brake cable  99  can attach to catch end  98  on the downwardly angled leg  94  to outer arm ends of each arm of a U brake  108 , such as those shown and described in U.S. Pat. No. 4,793,444 to Nagaono and U.S. Pat. No. 6,109,397 to Chen, which are incorporated by reference. Brake shoes (pads)  108  on the opposite ends of the U shaped arms of the U brake  100  can press against the rear rim  84  of the rear wheel  80  when the brake pedal  92  is depressed by the foot of a rider. The brake  90  can be oriented so that the brake shoes  108  can release and the pedal can angle upward to a neutral position when it is not depressed. The use of this U brake  100  with brake shoes  108  does not wear down the tire  82  since the brake shoes  108  rub against the rim  84  and not against the tire  82 . 
       FIG. 15  is a perspective view of the folded skateboard  1  of  FIG. 13  with attached lock cable  110 . Referring to  FIGS. 1 ,  1 A,  1 B,  2 ,  4 ,  6 ,  9 ,  12  and  15 , a lock cable  110  can be stored onboard the skateboard  1  by having one end inserted into an open end of a hollow angled bent member  44  on the frame  40  so that one end of the cable  110  can be pulled out when needed. A lock flange  118  with socket attached to a part of the frame  202  can attach the folded skateboard  1  to a support structure such as a bike rack  130  when the skateboard  1  is not being used. 
     The invention frame can be made from materials such as but not limited to steel, aluminum, composite, metal alloys, and the like. The deck can be made from materials such as but not limited to plastic, wood, metals, and the like. The wheel rims can be made from materials, such as but not limited to plastic, metal, and the like. 
       FIG. 16  is a perspective view of a rider  140  on the extended skateboard  1  of  FIG. 1 . 
       FIG. 17  is a perspective view of skateboard  1  with an attached handle  160 . 
       FIG. 18  is a perspective view of skateboard  1  with an attached sail  180 . Referring to  FIGS. 1A ,  17 , and  18 , the vertical portion of the stabilizing holt assembly  206  is to remain open at the top and act as a female receptacle to allow accessories to be attached such as a handle  160  or a sail  180 . The handle  160  can provide additional stability for an inexperienced rider and it can be removed when the rider&#39;s confidence increases. The sail  180  can provide propulsion by wind for the skateboard  1 . The three wheel lean-steer skateboard can be well suited to being modified to be powered by a motor, either gas or magnetic, which can drive the single rear wheel. 
     Although the invention describes a single pivot point at  64 ,  61   FIG. 1A , the invention can be practiced with more than one pivot point. 
       FIG. 19  is a side view of a steerable and foldable skateboard frame  300  with another folding mechanism.  FIG. 20  is a perspective view of the underside of the frame  300  of  FIG. 19 .  FIG. 21  is another perspective view of the underside of the frame  300  of  FIG. 20 .  FIG. 22  is a perspective view of only the folding mechanism of  FIGS. 19-21 .  FIG. 23  is another perspective view of the folding mechanism if  FIG. 22  partially folded.  FIG. 24  is another perspective view of the folding mechanism of  FIG. 22  fully folded.  FIG. 25  is a side view of the folding mechanism of  FIG. 24  fully folded. 
     Referring to  FIGS. 19-25 , a folding mechanism can include a pair of brackets  310  each having two parallel plates  320 ,  330 . Each of the plates  320 ,  330  can have a rear end  322 ,  332  fixably attached to outer ends of the left elongated member  42  and right elongated member  46  of the rear frame  40 . Across the top of the rear ends  322 ,  332  of the plates  320 ,  330  is a hinge  340  that is attached to the outer ends of the left elongated member  32  and right elongated member  36  of the front frame  30 . Reinforced holes  31  in the front frame elongated members  32 ,  36  align up with holes  321 ,  331  in the plates  320 ,  330  to allow for a quick-release type pin  350  to be inserted therein. A bottom plate  325  allows for the front frame  30  elongated members  32 ,  36  to rest against it so that the pin  350  can be passed through the holes  31 ,  321 ,  331 . 
     Referring to  FIGS. 19-25 , the skateboard frame  300  can be hinged at the lateral axis. The fulcrum of the hinge  350  lies on the top side of the elongated members  32 ,  36 ,  42 ,  46 . Brackets  310  attached to the outer ends of the elongated members  42 ,  46  of the rear frame  40  extend forward and overlap the rear portion of elongated members  32 ,  36  of the front frame  30 . The elongated members  32 ,  36  on the rear portion of the front frame  30  can contain reinforced holes  31  that align with matching holes  321 ,  331  in the bracket  310  attached to the front portion of the elongated members of the rear frame  40  so that a quick-release pin  350  can be inserted horizontally that lock the two plates  320 ,  330  into the unfolded position. Removing the pin  350  allows the hinge  340  to operate freely and the rear half of the skateboard  20 ,  40  will fold upward toward the front half  10  and  30 . 
     While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications which it has presumed in practice, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.