Patent Publication Number: US-6698776-B2

Title: Skateboard with simulated snowboard response

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a skateboard-like device configured to more closely simulate a snowboard, with wheels configured so that a user riding the skateboard on a hard surface experiences the sensation of riding a snowboard. 
     2. Related Art 
     Skateboards have been popular for some years for use in both recreation and physical training. Snowboards also have become very popular for similar purposes in mountainous areas with sufficient levels of snow. It has been recognized that producing a skateboard for use on hard surfaces that mimics the response of a snowboard would allow users to practice snowboarding techniques in locations without snow. Such a device would be desirable in locations that do not receive any snow, and locations that receive snow during only a few months of the year. 
     It will be appreciated that skateboards and snowboards are operated in different manners. Traditional skateboards utilize wheels mounted on the underside of a board in a variety of configurations, typically with pairs of wheels located near the front and rear of the skateboard. A rider manipulates a traditional skateboard by leaning toward the direction in which he wishes to turn and applying a lateral force to the board to produce incremental lateral sliding movements of the wheels, which results in the skateboard changing direction. 
     A rider manipulates a snowboard using two primary methods. First, the rider can manipulate the snowboard by leaning toward the direction in which he wishes to turn, thereby causing the inside edge of the snowboard to dig into the snow and force the snowboard into a turn. Alternately, the rider can manipulate a snowboard by utilizing the slick under-surface of the board and simply sliding the snowboard into a new direction while the majority of the underside of the board maintains contact with the snow. A rider can also manipulate a snowboard by using a combination of these two techniques. 
     U.S. Pat. No. 5,553,874 to Schouten et al. discloses a truck assembly for a roller board apparatus. The invention utilizes two separate axles on both the front and the rear of a platform. The axles are curved outwardly with a plurality of wheels of equal diameter separated by spacer elements. 
     SUMMARY OF THE INVENTION 
     It has been recognized that it would be advantageous to develop a skateboard for use on hard surfaces that mimics or simulates the response of a snowboard and allows users to practice snowboarding techniques in locations without snow. 
     The present invention provides an enhanced skateboard device with a platform mounted on wheels. In accordance with one aspect of the present invention, the wheels advantageously include wheels of varying diameter mounted on a common axle. Preferably, the wheels include one or more larger diameter wheels in the center, medium diameter wheels outside the larger wheels, and smaller diameter wheels outside the medium wheels so that the wheels have successively smaller diameters from a center of the platform or axel to the edges of the platform or ends of the axel. A rider can manipulate the enhanced skateboard by leaning toward the direction in which he wishes to turn, thereby engaging the progressively smaller diameter wheels on the common axle and producing a sensation similar to that experienced by a snowboarder when the inside edge of the snowboard digs into the snow during a turn. 
     In accordance with another aspect of the present invention, the wheels can include wheels with different frictional and/or compressibility characteristics. Preferably, the wheels include one or more harder wheels in the center, medium wheels on opposite sides of the harder wheel, and softer wheels on opposite sides of the medium wheels so that the wheels have a successively greater frictional and/or compressibility characteristic. Thus, the rider can manipulate the enhanced skateboard by sliding the enhanced skateboard while riding on the largest diameter wheels on the common axle, which have very low frictional characteristics, thereby imitating the response of a snowboard sliding into a new direction. The enhanced skateboard rider can also affect a turn by using a combination of these two techniques. In accordance with a more detailed aspect of the present invention, the device includes at least two sets of wheels of varying diameters mounted on their respective common axles. The wheels are configured so that the center wheels on a common axle have the largest diameter and the wheels on either side of the center wheels are of smaller diameter. The wheels on either side of these wheels are of even smaller diameter. This pattern may be repeated for any number of outer wheels as is desirable. 
     In accordance with another more detailed aspect of the present invention, the device may alternately or additionally include wheels mounted on a common axle made from materials with varying frictional and compressibility characteristics. The wheels are configured so that the center wheels on a common axle are made of a material having low frictional characteristics and low compressibility. The wheels on either side of the center wheels are made of a material with greater frictional characteristics and compressibility. The wheels on either side of these wheels are made of a material of even greater frictional characteristics and compressibility. 
     In accordance with another more detailed aspect of the present invention, the device may include one or more wheels mounted on a common axle having tapering diameters that decrease from the center of the board to the sides of the board. 
     In accordance with another more detailed aspect of the present invention, the device may include an additional set of one or more secondary wheels on a common axle mounted near either or both ends of the platform. These secondary wheels are of smaller diameter and allow the rider to lean the platform back onto the secondary wheels so that the front or rear set of wheels of varying diameter are not in contact with the ground. 
     Additional features and advantages of the invention will be apparent from the detailed description which follows, taken in conjunction with the accompanying drawings, which together illustrate, by way of example, features of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of an embodiment of the present invention. 
     FIG. 2 is a front elevational view of the wheels of an embodiment of the present invention, shown with the larger diameter center wheels contacting the ground, as when the board is traveling in a substantially straight path. 
     FIGS. 3 a  and  3   b  are front elevational views of the wheels of an embodiment of the present invention, shown with the smaller diameter outer wheels contacting the ground, as when the board is being turned. 
     FIG. 4 is a front elevational view of the wheels of an embodiment of the present invention, shown with the smaller diameter outer wheels contacting the ground and compressing accordingly, as when the board is being turned. 
     FIG. 5 is a side elevational view of an embodiment of the present invention, shown with the front-most wheels elevated and the smaller rear wheels contacting the ground. 
     FIG. 6 is a front elevational view of the wheels of an alternate embodiment of the present invention. 
     FIG. 7 is a front elevational view of the wheels of an alternate embodiment of the present invention. 
     FIG. 8 is a front elevational view of the wheels of an alternate embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION 
     For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the exemplary embodiments illustrated in the drawings, and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended. Any alterations and further modifications of the inventive features illustrated herein, and any additional applications of the principles of the invention as illustrated herein, which would occur to one skilled in the relevant art and having possession of this disclosure, are to be considered within the scope of the invention. 
     Referring now to FIGS. 1 through 8, wherein like reference numerals refer to like parts throughout, the skateboard device as shown in FIGS. 1 through 3 b , denoted generally by  10 , includes a platform  12  having a front and rear axles,  14  and  16  respectively, mounted transversely across the platform  12 . Front and rear sets of wheels  18  and  20  are mounted on the front and rear axles  14  and  16 , respectively. It is of course understood that either end of the skateboard device  10  may be designated as the front or rear. Secondary axles  22  are positioned forwardly and rearwardly of the forward and rear axles  16  and  18 , and also are mounted transversely across the platform  12 . Secondary sets of smaller diameter wheels  24  are mounted on the secondary axles  22 . The skateboard  10  is designed to be operated on hard surfaces  26 , such as concrete or asphalt. 
     The axles  14  and  16  can be coplanar with the platform  12  to allow the platform  12  to be closer to the ground. By moving the platform  12  closer to the ground, the skateboard  10  can more accurately imitate the response or feel of a snowboard, which is in direct contact with the snow covered ground on which a snowboard is operated. Openings can be formed in the platform  12  to accommodate the sets of wheels  18  and  20  which can protrude through the openings. Covers  15  and  17  can be placed over the openings in the platform  12  to prevent interference and/or injury between the sets of wheels  18  and  20  and the feet of the rider. The covers  15  and  17  also allow for the rider to step thereon in order to raise the opposite end in order to perform a “wheeley” maneuver. 
     Referring more particularly to FIGS. 2,  3   a  and  3   b , a preferred embodiment of the present invention is shown with the front set of wheels  18  mounted on the front axle  14 . It is of course understood that the rear set of wheels  18  can have a similar configuration to that of the front set of wheels  18  shown in FIGS. 2,  3   a  and  3   b . The set of wheels  18  preferably includes a plurality of wheels aligned or arrayed along the axle  14  with successively reduced diameters from a center of the axle  14  or platform  12 , to the edges of the platform  12  or ends of the axle  14 . Thus, innermost wheels can be larger than the outermost wheels. Specifically, the set of wheels  18  can include larger wheels  28  and  34  located generally in the center of the platform  12  or axle  14 , medium wheels  30  and  36  located on opposite sides of the larger wheels  28  and  34 , and smaller wheels  32  and  38  located on opposite sides of the medium wheels. The medium wheels  30  and  36  have diameters less than diameters of the larger wheels  28  and  34 , while the smaller wheels have diameters less than the diameters of the medium wheels  30  and  36 . The set of wheels  18  is symmetrical about a center of the axle  14  or platform  12  such that the diameter and composition of the larger wheels  28  and  34  are equal to each other, the diameter and composition of the medium wheels  30  and  36  are equal to each other, and the diameter and composition of the smaller wheels  32  and  38  are equal to each other. It is of course understood that the larger wheels  28  and  34  can be a single, larger wheel. In addition, wheels or knobs  39  can be formed on the ends of the axle  14  to form the outermost wheels of the set of wheels. The wheels or knobs  39  can have a semi-spherical shape. 
     By including the larger wheels  28  and  34  in the center of axle  14  or platform  12 , the skateboard  10  of the present invention can be operated much like a traditional skateboard when the rider is travelling in a substantially straight direction. However, when the rider turns the skateboard  10 , the unique aspect of the configuration of the wheels of the present invention allow the rider to more accurately experience the sensation of operating a snowboard. The set of wheels  18  of successively smaller diameter mounted on a common axle allows the skateboard  10  of the present invention to more accurately imitate the response of a snowboard. FIG. 2 represents the level horizontal cant of the axle  14  as the skateboard travels in a substantially straight direction. As is shown in FIG. 3 a , as the rider leans into a turn, the platform  12  and axle  14  tilt, and the medium wheel  30  makes contact with the surface or ground  26 . One of the larger wheels  28  may continue to contact the surface or ground  26  along with the medium wheel  30 , while the other larger wheel  34  may not. As shown in FIG. 3 b , as the rider continues to lean into a turn, the medium wheel  30  and smaller wheel  32  make contact with the surface or ground  26 , while both the larger wheels  28  and  34  may not. Alternatively, multiple wheels  28 ,  30  and  32  on one side of the platform  12  can contact the ground  26  as the rider tilts the platform. Therefore, the successively smaller wheels arrayed along the common axis allow the platform  12  to tilt with respect to the ground  26 , and thus simulate the orientation of a snowboard. 
     It is believed that wheels with successively smaller diameters offer successively greater rolling resistance and/or a different rolling response as a rider leans the skateboard  10  into a turn. For example, the speed with which the skateboard  10  is travelling decreases as the rider leans into a turn, and the skateboard  10  thus allows the rider to more fully experience the sensation of a snowboard digging into the snow as the rider leans into a turn. 
     In addition, the set of wheels  18  can include a plurality of wheels with different frictional characteristics to further enhance the ability of the present invention to simulate the drag experience of riding a snowboard. The set of wheels  18  can be formed of a material of successively higher frictional characteristics from the center of the platform  12  or axel  14  to the edges of the platform  12  or ends of the axel  14 . Thus, the outermost wheels can have higher frictional characteristics while the innermost wheels can have lower frictional characteristics. Specifically, the innermost wheels  28  and  34  can have low frictional characteristics, the intermediate wheels  30  and  36  can have greater frictional characteristics, and the outermost wheels  32  and  38  can have even greater frictional characteristics. As stated above, the frictional characteristics of the wheels can be determined by the material of the wheels. Alternatively, the frictional characteristics may be determined by the wheel&#39;s bearings. As the rider leans into a turn, as shown in FIGS. 3 a  and  3   b , the wheels with successively higher frictional characteristics, such as the intermediate and outer wheels  30  and  32 , make contact with the surface or ground  26 , while the innermost wheels  28  and  34  may or may not make contact with the surface  26 . 
     It is believed that wheels of successively greater frictional characteristics offer greater drag or rolling resistance and/or different rolling response. For example, the speed with which the skateboard  10  is travelling decreases due to the greater frictional characteristics of the intermediate and/or outer wheels as the rider leans into a turn, thus allowing the rider to experience the sensation of a snowboard digging into the snow as the rider leans into a turn. Additionally, because the innermost wheels  28  and  34  have very low frictional characteristics, they offer very little resistance to lateral movement. Therefore, the rider may spin the skateboard into a new position while the wheels  28  and  34  maintain contact with the hard surface  26 , thus further simulating the response of a snowboard. 
     Furthermore, the set of wheels  18  can include a plurality of wheels with different compressibility to further enhance the ability of the skateboard  10  of the present invention to simulate the experience of riding a snowboard. As shown in FIGS. 2 and 4, the set of wheels  18  can include wheels which are formed of a material of a successively higher compressibility from the center of the platform  12  or axel  14  to the edges of the platform  14  or ends of the axel  14 . Thus, the innermost wheels  28  and  34  can be more rigid or stiff, while the outermost wheels  32  and  38  can be more compressible or flexible. Specifically, the innermost wheels  28  and  34  can have lower compressibility or greater rigidity, the intermediate wheels  30  and  36  can have greater compressibility than the innermost wheels, and the outermost wheels  32  and  38  can have even greater compressibility than the intermediate wheels. As stated above, the compressibility of the wheels can be determined by the material of the wheels. As the rider leans into a turn, the wheels with successively higher compressibility, such as intermediate and outer wheels  30  and  32 , make contact with the surface of ground  26  and may compress. As the wheels  30  and  32  compress, they spread or expand laterally outward and contact a greater surface area of the ground, as shown in FIG.  4 . 
     It is believed that wheels of successively higher compressibility will offer successively greater rolling resistance. Consequently, the speed with which the skateboard  10  is travelling decreases as the rider leans into a turn, and the rider thus experiences the sensation of a snowboard digging into the snow as the rider leans into a turn. 
     The use of the secondary axles  22  and secondary sets of wheels  24  is shown in FIG.  5 . The rider can use the secondary axle  22  and secondary sets of wheels  24  to perform “wheely” maneuvers, in which the front or rear sets of wheels  18  and  20  are completely removed from contact with the hard surface  26  while the opposite set of wheels remains in contact with the hard surface  26 . The rider can tilt the platform  12  forwardly or rearward about the axle  14  or  16  until contact is made with the secondary set of wheels  24 , thereby increasing the rider&#39;s ability to control the skateboard  10  while performing “wheely” maneuvers. 
     In addition, the secondary sets of wheels  24  can include wheels of different diameters, and/or wheels of different frictional or compressibility characteristics. Thus, the rider can pivot the platform  12  rearwardly to perform a “wheely” maneuver, and at the same time pivot the platform  12  laterally onto smaller diameter wheels on both the rear axle  16  and the secondary axle  22 . 
     Referring to FIG. 6, an alternative configuration of a wheel  40  is shown with a tapering diameter that can be used to further enhance the ability of the present invention to simulate the response of a snowboard. The wheel  40  is shaped to have a symmetrically decreasing diameter that reduces from its largest diameter in the center of the wheel  40  outward along the axle  14 . Thus, the wheel  40  has a continuous surface area with a substantially decreasing diameter along its width from the center to the ends. By using such a wheel  40 , the present invention allows the rider a smooth transition from travelling in a substantially straight direction, when the center of the wheel with the largest diameter of wheel  40  contacts the hard surface  26 , to leaning into a turn, when the end of the wheel with the smallest diameter contacts the hard surface  26 . As the wheel  40  rolls on a successively smaller diameter, it is believed that the rolling resistance of wheel  40  will increase, causing a decrease in the speed with which the skateboard  10  is travelling. This smooth transition from a faster to a slower speed as the rider leans into a turn further simulates the response of a snowboard as the snowboard digs into the snow during a turn. 
     Furthermore, a similar result may be achieved by using multiple wheels forming a tapered diameter. FIG. 7 shows an alternate embodiment of the present invention wherein the set of wheels  42  on the axle  14  are shaped such that their diameters continuously reduce from the center of the set of wheels  42  outward along the axle  14 . The largest diameter of wheel  48  is smaller than the smallest diameter of wheel  46 , and the largest diameter of wheel  46  is smaller than the smallest diameter of wheel  44 . The set of wheels  42  is symmetrical about the center of the axle  14  such that the shape and composition of wheel  50  are equal to that of wheel  44 , the diameter and composition of wheel  52  are equal to that of wheel  46 , and the diameter and composition of wheel  54  are equal to that of wheel  48 . 
     The collective shape of the set of wheels  42  allows the rider a smooth transition from travelling in a substantially straight direction, when wheels  44  and  50  are in contact with the hard surface  26 , to leaning into a turn, when wheels  44 ,  46  and  48  may all be in contact with the hard surface  26 . As more wheels contact the hard surface  26 , the collective rolling resistance of the set of wheels  42  increases, causing a decrease in the speed with which the skateboard  10  is travelling. This smooth transition from a faster to a slower speed as the rider leans into a turn simulates the response of a snowboard as the snowboard digs into the snow during a turn. 
     It is of course understood that the basic configuration of the wheels and axels of the present invention can be modified. For example, a vertical support  60  can be provided between the wheels as shown in FIG.  8 . In addition, it is understood that the axle  14  of previous configurations can be replaced with two axles,  56  and  58 . The axles  56  and  58  are supported on both ends, with the center vertical support  60  constraining both axles  56  and  58  in the center of the platform  12 . Alternately, axle  14  could be used as in previous configurations, with center vertical support  60  constraining axle  14  at its center. A more stable mounting system can thus be used with any of the preceding systems of wheels. In addition, it is understood that the wheels can have different sizes, such as diameters and widths, and that different numbers of wheels can be used. 
     As illustrated in FIG. 6, in accordance with another feature of the present invention, a diameter of the at least one wheel  40  is selected to form a continuous, curved line  72  which extends along a contact surface of the wheel  40  from a central  72  portion of the wheel to a distal  74  portion of the wheel. This curved contact surface provides a gradual, and continually varying contact interface between the skateboard and the riding surface  26  to more effectively provide a snowboard response by the skateboard. 
     In the embodiment illustrated in FIG. 7, the at least one wheel includes a set of wheels  42  and a diameter of each wheel of the set of wheels is selected to form a segmented, curved line  80  extending across contact surfaces of the wheels from a central  82  to a distal  84  portion of the axle. Selecting the diameters of the wheels accordingly provides a continuous, curved contact interface between the wheels and the riding surface  26  to allow a user to gradually turn or tilt the skateboard to more effectively simulate the response of a snowboard. 
     As shown in FIG. 3 a,  the wheels of the set of wheels  18  can include wheels having different diameters. The diameter of each wheel can be selected to position a contact surface  92  of each wheel along a segmented, curved line  90  extending across contact surfaces  92  of the wheels from a central  94  to a distal  96  portion of the common axle. Positioning the contact surfaces  92  in such a fashion provides a continually curved contact interface between the wheels and the riding surface  26 . This curved contact interface provides a rider gradual transition from one incline of the board to another, which allows the rider to experience a snowboard-like response from the skateboard. 
     It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the spirit and scope of the present invention and the appended claims are intended to cover such modifications and arrangements. Thus, while the present invention has been shown in the drawings and fully described above with particularity and detail in connection with what is presently deemed to be the most practical and preferred embodiment(s) of the invention, it will be apparent to those of ordinary skill in the art that numerous modifications, including, but not limited to, variations in size, materials, shape, form, function and manner of operation, assembly and use may be made, without departing from the principles and concepts of the invention as set forth in the claims.