Patent Publication Number: US-8523205-B2

Title: Swing skateboard

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to a skateboard, and more particularly to a swing-type skateboard. 
     2. Description of the Related Art 
     Currently, the most popular skateboard is the skateboard with four rollers. The four rollers are respectively positioned at a front end and a rear end of the skateboard to provide very good stability in skating. However, in use of such skateboard, a user must tread the ground with one foot to help in skating and moving the skateboard forward. Moreover, the operational sensitivity of such skateboard is poor. In addition, the board body of such skateboard is made of wooden board. It is hard to process the wooden board and the cost is high. As a result, the board body of the skateboard generally has a quite monotonous configuration without changeability. Furthermore, the adoption of wooden board as the material of the board body leads to environmental protection problem due to tree logging. 
     Another type of skateboards is provided. Such skateboard has only two rollers respectively positioned at the front end and the rear end thereof. However, the front and rear rollers of such skateboard are arranged in alignment and such skateboard contacts the ground only at two points. Therefore, such skateboard has low stability and is hard to use. Only a very experienced player can play such skateboard well. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary object of the present invention to provide a swing skateboard, which has very good operational sensitivity and stability. A user can wiggle his/her body to tilt the skateboard and drive the skateboard forward. 
     It is a further object of the present invention to provide a swing skateboard, which has enhanced structural strength and is able to bear greater load. 
     To achieve the above and other objects, the swing skateboard of the present invention includes a board body, a front roller unit and a rear roller unit. The board body is an elongated body. The front roller unit has a front roller fork rotatably disposed at a front end of the bottom face of the board body, and a front roller rotatably mounted on the front roller fork. Accordingly, the front roller unit can 360-degree swivel. The rear roller unit has a rear roller shaft mounted under the bottom face of the board body, and two rear rollers respectively rotatably disposed at two ends of the rear roller shaft. 
     Accordingly, the skateboard contacts the ground at three points to have better stability for a user to conveniently operate the skateboard. Especially, a user can wiggle his/her body to tilt the board body leftward and rightward and make the front roller unit responsively laterally swing so as to urge the skateboard to naturally move forward. 
     The bottom face of the board body is formed with raised/recessed reinforcement structures to enhance load capacity of the skateboard. The board body can be made of plastic material. 
     The present invention can be best understood through the following description and accompanying drawings, wherein: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective assembled view of a preferred embodiment of the present invention; 
         FIG. 2  is a perspective exploded view of the preferred embodiment of the present invention; 
         FIG. 3  is a bottom perspective view of the preferred embodiment of the present invention according to  FIG. 1 ; 
         FIG. 4  is a bottom perspective view of the top board of the present invention; 
         FIG. 5  is a side view of the skateboard of the present invention; 
         FIG. 6  is a longitudinal sectional view of the skateboard of the present invention; 
         FIG. 7  is a sectional view taken along line  7 - 7  of  FIG. 6 ; 
         FIG. 8  is a front view of the skateboard of the present invention, showing that the board body is tilted to one side; 
         FIG. 9  is a top view of the skateboard of the present invention according to  FIG. 8 , showing that the front roller unit swings to one side; 
         FIG. 10  is a front view of the skateboard of the present invention, showing that the board body is tilted to the other side; and 
         FIG. 11  is a top view of the skateboard of the present invention according to  FIG. 10 , showing that the front roller unit swings to the other side. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Please refer to  FIGS. 1 to 3 . According to a preferred embodiment, the swing skateboard of the present invention includes a board body  10 , a front roller unit  20  and a rear roller unit  30 . 
     The board body  10  is an elongated body having a front end and a rear end. The board body  10  includes a bottom board  11  and a top board  12  disposed on a top face of the bottom board  11 . In this embodiment, the board body  10  is made of plastic material. Preferably, the material of the bottom board  11  and the top board  12  is Acrylonitrile-Butadiene-Stryene (ABS). Alternatively, the board body  10  can be made by means of integral injection molding. 
     Two elongated ribs  111  are disposed under a bottom face of the bottom board  11  as shown in  FIGS. 3 and 7 . The two ribs  111  are positioned on two sides of the bottom board respectively and longitudinally extend along the bottom board. An elongated recess  112  is formed between the two ribs  111  and positioned at a center of the bottom board. Multiple support diaphragms  113  are disposed in the recess  112 . Due to the ribs  111  and the recess  112 , the bottom board  11  has a cross section with a raised/recessed configuration for increasing structural strength and load capacity of the bottom board  11 . In addition, a protrudent seat  114  is disposed at the front end of the bottom face of the bottom board  11 . The protrudent seat  114  has a rearward upward inclined slope  115  as shown in  FIG. 5 . As shown in  FIG. 6 , the protrudent seat  114  can be integrally formed with the board body  10 . The inclination angle θ of the slope  115  ranges from 10 degrees to 30 degrees, and preferably from 15 degrees to 25 degrees. The ribs  111  are positioned behind the protrudent seat  114 . The bottom board  11  has a hollow interior for reducing the weight. Multiple diaphragms  116  are disposed in the interior of the bottom board. The protrudent seat  114  is such shaped as to increase the structural strength of the bottom board  11  and enhance the impact strength of the board body  10 . The ribs  111  and the recess  112  are positioned between the front roller unit  20  and the rear roller unit  30 . 
     The top board  12  has a bottom face under which multiple diaphragms  122  are disposed as shown in  FIG. 4 . The diaphragms  113 ,  116  and  122  all serve to increase the structural strength of the bottom board  11  and the top board  12 . The top board  12  is fixedly disposed on the top face of the bottom board  11  by means of screws or any other suitable measure. 
     An anti-slip member  14  in the form of a thin sheet has a configuration identical to that of the top face of the board body  10 . A rough anti-slip face is disposed on atop face of the anti-slip member  14 . The anti-slip member  14  is fixedly disposed on the top face of the top board  12  by means of such as adhesion to provide anti-slip effect. 
     The front roller unit  20  has a front roller fork  21  and a front roller  22  pivotally disposed on the front roller fork  21 . A rotary shaft  211  of the front roller fork  21  is pivotally disposed on the slope  115  of the protrudent seat  114  of the bottom board  11  as shown in  FIG. 5 . Accordingly, the front roller fork  21  can 360-degree swivel around the rotary shaft  211  under the bottom board for a user to conveniently control the moving direction of the skateboard. Due to the slope  115  of the protrudent seat  114 , the rotary shaft  211  of the front roller fork  21  is not upright, but rearward inclined by the inclination angle θ. 
     The rear roller unit  30  has a roller seat  31  fixedly disposed at the rear end of the bottom face of the bottom board  11 ; a central shaft  32  having a top end connected with the roller seat  31 ; a rear roller shaft  33  mounted at a bottom end of the central shaft  32 , and two rear rollers  34  respectively pivotally disposed at two ends of the rear roller shaft  33 . The rear roller unit  30  is arranged under an inclined section B of the bottom board  11  as shown in  FIG. 5 . The inclined section B is rearward upward inclined by an inclination angle δ, which ranges, for example, from 5 degrees to 15 degrees. Accordingly, the central shaft  32  is also rearward inclined by the inclination angle δ. 
     Referring to  FIGS. 8 to 11 , in use, a user stands on the board body  10  of the skateboard and wiggles his/her body to change the position of the gravity center. Under such circumstance, the board body  10  is leftward or rightward tilted to make the front roller fork  21  of the front roller unit swing leftward or rightward. Accordingly, the user can move the skateboard forward without treading the ground with his/her foot to move it forward. As aforesaid, the rotary shaft  211  of the front roller fork  21  is inclined by an inclination angle, whereby the front roller fork can sensitively swivel. Also, the central shaft  32  of the rear roller unit  30  is inclined by an inclination angle. This makes it easier to bias the rear roller unit relative to the board body  10 . 
     According to the above arrangement, the present invention has the following advantages:
     1. The front roller unit  20  and the rear roller unit  30  of the present invention provide a non-collinear three-point support effect for the skateboard. Therefore, the skateboard has very good stability and is easy to use and operate.   2. A user can wiggle his/her body to tilt the board body  10  and make the skateboard move forward without treading the ground with his/her foot. The front roller fork  21  can 360-degree swivel around the rotary shaft  211  relative to the board body. Therefore, the skateboard has very good operational sensitively for the user to conveniently control the moving direction of the skateboard.   3. The board body  10  of the present invention is made of plastic material by injection molding. It is easy and quick to manufacture and process the board body  10 . Therefore, the manufacturing cost is lowered. Moreover, the board body  10  can be formed with various configurations without causing the environmental protection problem due to tree logging.   4. The board body  10  of the present invention is designed with multiple reinforcement structures. For example, the board body  10  has the protrudent seat  114 , the ribs  111 , the recess  112  and the diaphragms  113 ,  116 ,  122  disposed on the top board and the bottom board. All these structures can increase the structural strength and strain strength of the board body  10  for the board body  10  to bear the weight of human body and treading force.   

     In conclusion, the swing skateboard of the present invention has very good operational sensitivity and stability and can be formed with various configurations. 
     The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.