Patent Publication Number: US-2010123295-A1

Title: Skateboard

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/078,423 filed on Jul. 6, 2008 and is entitled “SKATEBOARD.” The complete disclosure of the above-identified patent application is hereby incorporated by reference for all purposes. 
    
    
     BACKGROUND  
     Skateboards are generally provided with a deck and two pairs of wheels, with front and rear trucks each coupling one pair of the wheels to the deck. The skateboard rolls as propelled by a rider and/or in a downhill direction, and the trucks steer the wheels in the direction that the rider tilts the deck. Typical skateboards are suited only to low speed operations because of the lack of stability from the small size of the wheels and the placement of the deck over the wheels. Some skateboards, such as longboards, are more suited to cruising operation, and may be more suitable for higher speeds and are used for transportation. However, even longboards usually lack a braking mechanism, which further detracts from high speed operation. Skateboards are also cumbersome to carry and to stow due to their size and shape. 
     SUMMARY  
     The disclosed skateboard includes a deck with an upper surface that is close in elevation to the axes of rotation of the wheels. For example, the upper surface may be slightly above, generally level with, or below the axes of rotation of the wheels, or may be at another elevation as suited to a desired application of the skateboard. The deck may have a uniform elevation, or may include portions at different elevations. For example, the deck may include a central portion at a low elevation and raised front and/or rear portions to facilitate mounting of trucks beneath the deck while maintaining a low elevation for the central portion of the deck. 
     The skateboard of the present disclosure includes trucks that preferably are mounted to the deck and each truck connects an axle to the deck so that the wheels mounted on the axle are steered by a tilting of the deck. For example, each truck may be mounted by a kingpin coupled to the deck at an angle offset from vertical, with a pair of torsion springs, or other cushions or shock absorbers alongside the kingpin biasing the wheels to a neutral steering position. The angled mount of the kingpin causes the wheels to diverge from the neutral position when the deck is tilted. A stop may be provided adjacent the trucks to limit the divergence of the wheels from the neutral position. 
     The angled mount may be provided by locating a hole for each kingpin in an angled portion of the deck, for example, in front and rear downwardly-angled portions. The kingpin hole may be aligned with other holes or cavities in the deck to facilitate a molded construction for the deck. 
     The skateboard may also include a brake mounted to the board, preferably adjacent a rear portion of the deck. The brake may include a foot pedal coupled to a brake pad that contacts the ground in an operative condition. Such a brake may be mounted in an aperture through the deck and provided with a pivot axis and a mechanism to bias the brake to a non-operative condition. 
     The presently-disclosed deck may be provided with a two-segment construction with a central hinge coupling the two segments to allow for reconfiguring the skateboard between an unfolded position for riding and a folded position for carrying and stowing. A carrying handle may be provided on the skateboard, e.g., by being built into the hinge, to facilitate a user&#39;s transporting the skateboard when not in use. Preferably, the wheels are mounted alongside the deck, i.e., to the outside of right and left edges of the deck, and at different distances from the central hinge, so that the wheels do not interfere with folding the deck at the hinge. 
     The advantages of the present invention will be understood more readily after a consideration of the drawings and the Detailed Description. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         FIG. 1  is a perspective view of a skateboard of the present disclosure, showing a deck that includes a hinge connecting front and rear segments, two trucks mounted beneath the deck, four wheels coupled to the trucks, and a foot-operable brake. 
         FIG. 2  is a side elevation of the skateboard of the present disclosure, with the near-side wheels removed to show the trucks beneath the deck and an aperture through a rear portion of the deck, through which extends an arm of the brake, and also showing a pivot axis of the hinge connecting the front and rear segments of the deck. 
         FIG. 3  is a side elevation similar to that of  FIG. 2 , with the brake illustrated in an operative condition with the pad contacting the ground. 
         FIG. 4  is an exploded view of the components of the deck, trucks, wheels, axles, brake, hinge, a pair of kingpins for mounting the trucks, two pairs of torsion springs for neutrally biasing the trucks, a pivot pin for the brake, and a carrying handle built into the hinge. 
         FIG. 5  is a partial perspective view of one end of a skateboard according to the present disclosure, showing the tilting motion of the deck producing the steering movement of the truck and wheels, and a pair of stops on the deck for limiting the steering motion of the truck. 
         FIG. 6  is a side view of a skateboard of the present disclosure in a folded condition, with the lower surfaces of the deck folded at the hinge towards one another and with the carrying handle deployed for hand transport, and the two pairs of wheels adjacent one another. 
         FIG. 7  is a perspective view from beneath the skateboard illustrating the alignment of cavities in the deck with a through hole for the kingpin. 
     
    
    
     DETAILED DESCRIPTION  
     An exemplary skateboard according to the present disclosure is indicated generally at  10  in  FIG. 1 . A deck  12  of board  10  provides a support platform  14  for a rider or user (not shown). Deck  12  may be formed of any suitable material, e.g. molded plastic, with or without fiber or other reinforcement, or a multi-ply, laminate or other construction suited for the desired style of skateboard riding. 
     A pair of front wheels  16 , which define a front axis of rotation FA, may be coupled to deck  12  by a front truck  18 . A pair of rear wheels  20 , which define a rear axis of rotation RA, may be coupled to deck  12  by a rear truck  22 . Typically, wheels  16  and  20  are larger than the standard wheels of 2-inches to 4-inches in diameter used in skateboards and longboards. Although other combinations and sizes may be used, wheels  16  and  20  are typically at least about 5-inches in diameter or as large as 7-inches in diameter, or larger as suited to the particular skateboard design. Use of larger wheels typically allows a higher speed for the skateboard for a given force applied to the skateboard. Wheels  16  and  20  typically are about 1-inch wide, although other widths may be used, and thus a typical ratio of wheel diameter to width is at least about five and preferably about seven, although other sizes may be used. Wheels  16  and  20  are typically all the same size, although different combinations may be used. 
     The front and rear trucks may be formed of molded plastic, e.g., the same molded plastic as the deck, or formed of any other material suited to the skateboard&#39;s requirements. The wheels may be formed of any suitable material, such as polyurethane tires mounted to a plastic rim, and typically are provided with a bearing mounted in a hub. 
     The user typically stands on a central portion  24  of support platform  14 , on an upper surface  26  of the support platform. Central portion  24  is between a front portion  28  and a rear portion  30  of support platform  14 . Front portion  28  includes an upper surface  32  and rear portion  30  includes an upper surface  34 . Preferably, upper surface  32  of front portion  28  and upper surface  34  of rear portion  30  are raised above upper surface  26  of central portion  24  of support platform  14 . The upper surfaces of the front and rear portions may be raised, for example at their associated axes of rotation, by about 2-inches to 4-inches. Alternatively, the front and rear portions may be raised, kept level, or lowered in different combinations and to any height as suited for the desired skateboarding purpose. Upper surfaces  32 ,  34  of front and rear portions  28 ,  30  may provide a surface for the rider&#39;s feet, although in typical operation the feet would not be placed there. 
     Preferably, front portion  28  extends over front axis of rotation FA and rear portion  30  extends over rear axis of rotation RA. As can best be seen in  FIGS. 2 and 3 , raising the front and rear portions of the deck above the central portion allows the central portion to be substantially lower in elevation above a ground level GL as would otherwise be the case. Typically, upper surface  26  of central portion  24  is substantially level with at least one of the front and rear axes of rotation, and preferably upper surface  26  of central potion  24  is less than one wheel radius R above the front axis FA and rear axis RA of rotation. Alternatively, central portion  24  may be placed at any elevation relative to the front and rear axes of rotation. Upper surface  26  of central portion  24  may remain level from the front portion to the rear portion, or may be provided with a slope, such as the downward slope shown in  FIGS. 2 and 3 . A downward slope for the central platform tends to provide the rider with a more level platform while the rider is endeavoring to travel uphill with one foot on the deck and the other foot used to push along the ground. Also, on flat ground, the downward slope facilitates the rider&#39;s propelling the board forward because the slope allows the rider to lean forward which enhances balance and comfort during forward motion. 
     As may also be seen in  FIGS. 1-3 , front portion  28  may be designed with a curved shape including a first curvature  36  that, in a forward direction, angles upwardly from central portion  24 , and a second curvature  38  that, angles downwardly. Similarly, rear portion  30  may be designed with a curved shape including a first curvature  40  that, in a rearward direction, angles upwardly from central portion  24 , and a second curvature  42  that angles downwardly. It will be noted that for the embodiment of the skateboard in  FIGS. 1-3 , the first curvatures on the front and rear portions are placed closer to the central portion of the board than are the trucks. Preferably, second front curvature  38  and second rear curvature  42  angle downwardly at substantially equivalent, complementary angles. Alternatively, the front and rear portions may be provided with any shape as suited to a particular application. 
     Front truck  18  may be coupled to deck  12  adjacent front portion  28 , for example, at second front curvature  38 . Rear truck  22  may be coupled to deck  12  adjacent rear portion  30 , for example, at second rear curvature  42 . Coupling the trucks at these complementarily-angled locations provides for complementary steering of the wheels in response to the rider&#39;s tilting the deck. 
     For example, as best seen in  FIGS. 2 ,  4 , and  5 , front truck  18  may be attached by a kingpin  44  to deck  12  at second curvature  38  of front portion  28 . Kingpin  44  may be installed in a through hole  46  through the deck. Through hole  46  nay be normal to upper surface  32  at second curvature  38 , in which case kingpin  44  will be offset from vertical to the same degree as second curvature  38  is angled with respect to horizontal. Such angling of kingpin  44  results in a side-to-side tilting of deck  12  being translated into a redirection of wheels  16  as will be explained more fully below. 
     Similarly, a rear kingpin  48  may be attached at second curvature  42  of rear portion  30  through a hole  50 , typically with geometry complementary to that for the front truck. For example, both the second front curvature  38  and second rear curvature  42  may angle downwardly at about 30-degrees, providing the kingpins with an offset from vertical of about 30-degrees. Alternatively, the trucks and kingpins may be configured with different geometries as suited to a desired steering setup. 
     As best seen in  FIG. 5 , which illustrates a right hand turn with solid arrows and a left hand turn with dashed arrows, a downward tilting RT of a right edge RE of deck  12  causes a right hand steering RS of front truck  18 . Similarly, a downward tilting LT of a left edge LE of deck  12  would cause a left hand steering LS of front truck  18 . Typically, rear truck  22  is provided with a complementary mounting geometry that steers the rear wheels in the opposite direction of the front wheels, which tends to produce a circular path for the skateboard. Alternatively, other modes of steering may be provided, such as identically configured truck mounts for crab steering. 
     Front truck  18  may be provided with an axle, such as two-piece axle  52  and a stop  54  located adjacent the axle, for example on the front of the truck at an offset from the center of the truck, as shown in  FIG. 5 . Stop  54  may cooperate with a stop  56  at the front end of deck  12 , e.g., at the center of the deck as shown in  FIG. 5 . The stops  54 ,  56  may cooperate to limit a divergence of the front axle from alignment with the deck, as illustrated for a right hand turn in  FIG. 5 . A second set of stops, including stop  58  on truck  18  may be provided in another location on truck  18  to limit, in cooperation with a stop (not shown) on deck  12 , a divergence of the front axle from alignment with the deck for a left hand turn. Similarly, rear truck  22  may be provided with an axle, such as two-piece axle  60 , and one or more sets of stops  62 ,  64 ,  66  for a similar limit on steering divergence of the rear truck and axle ( FIG. 4 ). 
     Front truck  18  may be provided with a pair of torsion cylinders, such as springs  68  coupled to the support platform. For example, truck  18  may include a pair of cavities or pockets  70 , each on one side of kingpin  44 , into which one end of each torsion spring  68  is inserted. An opposing pair of pockets  72  may be provided in deck  12  adjacent front portion  28  to receive the other end of each torsion spring. 
     Rear truck  22  may be provided with a similar pair of torsion springs  74  and pockets  76  on the rear truck coordinated with pockets  78  in deck  12  adjacent rear portion  30 . Preferably, each pair of springs  68  and  74  are arrayed substantially parallel to, and on opposite sides of the respective kingpin. Generally speaking, the torsion springs flexibly couple each axle to the deck. Alternatively, other tilt and steering control mechanisms may be provided in either or both of the front and rear portions of the deck. 
     Skateboard  10  may include a brake  80  mounted to support platform  14 , preferably adjacent rear portion  30 . Brake  80  may be foot-operated, as illustrated in  FIG. 2  (in the non-operative condition) and  FIG. 3  (in the operative condition). Brake  80  may include a ground-contacting pad  82 , a pedal  84 , an arm  86  interconnecting the arm and the pad, and a pivotal mount  88  to provide for the movement between the operative and non-operative conditions. Preferably, an aperture  90  is provided through the deck and arm  86  extends through aperture  90 . Typically, the brake will also include a biasing mechanism, such as a spring (not shown) to bias the brake to the non-operative condition. Alternatively, brake  80  may be provided in a different location on support platform  14  or be differently configured for a desired riding application. 
     As best seen in  FIGS. 4 and 6 , deck  12  may be formed of more than one segment, such as front segment  92  and rear segment  94  that may be joined at a hinged portion  96 . For example, front segment  92  may include front portion  28  and rear segment  94  may include rear portion  30 , with central portion  24  divided between the front and rear segments. 
     Hinged portion  96  may include a front hinge half  98  and a rear hinge half  100 , each coupled to a respective segment, e.g., by bolts  102 , washers  104 , and nuts  106 . Hinge halves  98  and  100  may be coupled by a pin  108  fastened by a nut  110  or other hardware in a manner allowing deck  12  to fold at hinged portion  96  as shown in  FIG. 6 . As noted above, deck  12  defines right side edge RE and left side edge LE, and wheels  16  and  20  may be mounted outside of the side edges. 
     Preferably, hinged portion  96  is offset from the center of central portion  24  so that, when the deck is folded at the hinged portion, wheels  16  and  20  do not interfere with the folding, but instead are separated, or just touching, as shown in  FIG. 6 . In the folded position, a front underside  112  of deck  12  located in front of the hinged portion and a rear underside  114  of deck  12  located to the rear of the hinged portion may be substantially parallel to, and facing one another. Preferably, skateboard  10  is held in the unfolded position by gravity and by a pair of opposed flanges  116 ,  118 , one on each of hinge halves  98  and  100 . A latch or other means may be used to releasably fix the skateboard in either or both of the folded and unfolded positions. Preferably, only gravity holds the skateboard in the folded position. 
     A handle  120  for carrying the skateboard, may be provided at any convenient location on the skateboard. For example, handle  120  may be located in hinged portion  96  and may be coupled at a pair of hubs  122  on a pair of handle arms  124  to hinge pin  108 . Preferably, the handle becomes accessible for carrying when deck  12  is folded at hinged portion  96 , and, in a riding configuration, such as the unfolded position, handle  120  is substantially below upper surface  26  of support platform  14 . 
     As best seen in  FIG. 7 , through hole  46  in front segment  92 , that is configured to receive kingpin  44 , may be aligned in a direction FMD that corresponds to the direction FMC of cavities  126  between ribs  128 . Such alignment of the kingpin hole and the cavities facilitate molding of front segment  92  because it allows the hole and cavities to be formed between two halves of a mold and removed from the mold without a requirement for slides or other movable in-mold hardware. Rear segment  94  may be provided with a similar alignment for the kingpin hole and cavities. 
     It is believed that the disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in its preferred form, the specific embodiments thereof as disclosed and illustrated herein are not to be considered in a limiting sense as numerous variations are possible. The subject matter of the inventions includes all novel and non-obvious combinations and subcombinations of the various elements, features, functions and/or properties disclosed herein. Similarly, where any claim recites “a” or “a first” element or the equivalent thereof, such claim should be understood to include incorporation of one or more such elements, neither requiring nor excluding two or more such elements. Further, ordinal indicators, such as first, second or third, for identified elements are used to distinguish between the elements, and do not indicate a required or limited number of such elements, and do not indicate a particular position or order of such elements unless otherwise specifically indicated. 
     Inventions embodied in various combinations and subcombinations of features, functions, elements, and/or properties may be claimed through presentation of new claims in this or a related application. Such new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower or equal in scope to the original claims, are also regarded as included within the subject matter of the inventions of the present disclosure. The described examples are illustrative and directed to specific examples of apparatus and/or methods rather than a specific invention, and no single feature or element, or combination thereof, is essential to all possible combinations. Thus, any one of various inventions that may be claimed based on the disclosed example or examples does not necessarily encompass all or any particular features, characteristics or combinations, unless subsequently specifically claimed.