Patent Publication Number: US-2010127468-A1

Title: Skateboard

Description:
TECHNICAL FIELD 
     The present invention relates to a skateboard, and more particularly, to a skateboard that can freely turn with a very short turning radius and can be self-propelled by a user without direct contact to the ground. 
     BACKGROUND ART 
     Conventional skateboards are disclosed in the registered Korean Patent Publications No. 10-0394848 titled “Skateboard having a direction-caster” or No. 10-0612427. In the above skateboards, front and rear plates are coupled by a connection member that is bendable and elastically restorable. The front and rear plates include direction casters on bottoms thereof wherein the direction casters can be turned toward the direction in which the plates are inclined. Accordingly, a turning radius of the skateboard can be minimized and function of the direction casters can be maximally utilized by independently steering front and rear wheels of the front and rear plates. 
     DISCLOSURE OF INVENTION 
     Technical Problem 
     However, when the front and rear plates are separately provided and connected to each other in a spaced state in the above conventional skateboards, there has been problems as below. 
     Total available area of the plate is reduced and thus the space for the user&#39;s feet becomes narrow. Accordingly, the user cannot play various riding skills that are unique in the skateboards. 
     Particularly, the user cannot use the middle portion of the skateboard and thus cannot place his/her foot on the middle portion. Accordingly, the user cannot play the grinding skill (skill of sliding a corner of an object using right or left edges of the skateboard) that can be played by conventional classical skateboard. 
     In addition, in the case where the space between the front and rear plates is narrow, there is caused a safety problem that a portion of the user&#39;s body may be caught in the space when the front and rear plates are bent oppositely to each other. 
     Technical Solution 
     Accordingly, an object of the present invention is to provide a skateboard, which includes: a diagonally bendable rectangular plate whose middle portion is not bent; and a member provided at right and left edges of the plate, where the member cannot be vertically bent. 
     Advantageous Effects 
     The skateboard according to the present invention produces following effects. 
     The plate of the skateboard is formed of a single plate without being divided into the front and rear plates and the middle portion of the plate is not folded or bent. Thus, the user can utilize the entire plate as a foothold and run using side edges of the skateboard with a very short turning radius and propel the skateboard by the user without being contacted to the ground. 
     In addition, the skateboard can maintain the shape of single plate as the same as the classical skateboard. Accordingly, the user can easily keep balance by stepping on the skateboard with oppositely inclined both feet. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a view illustrating front, side and bottom; 
         FIG. 2  is a plan view illustrating only a plate  10  without a driving wheel, where section boundaries C 1  and C 2 , and wheel fixing parts  20 P are shown as dotted lines, the section boundaries C 1  and C 2  being formed when the plate is diagonally bent; 
         FIG. 3  is a side view illustrating diagonal bending operation of the plate; 
         FIG. 4  is a exemplary view illustrating various examples of a support unit  30 , where “A” shows the support unit provided on the bottom and “B” shows the support unit provided on the upper surface and “C” shows the support unit provided at edges and “D” shows the support unit inserted into the edges and “E” shows the support unit formed by extending the edges vertically and “F” shows the support unit formed by thickening the edges; 
         FIG. 5  shows plates according to another embodiment of the present invention, where “A” and “B” are bottom views; 
         FIG. 6  is a view illustrating front and bottom; 
         FIG. 7  is a view illustrating the front and bottom of the plate; 
         FIG. 8  is a view illustrating the plate provided with a reinforcing support unit (EF), where “A” is a bottom view and “B” is a perspective bottom view; 
         FIG. 9  is a bottom view of the plate; 
         FIG. 10  is a view illustrating front, side and bottom; 
         FIG. 11  is a side view illustrating diagonal bending operation of the plate; 
         FIG. 12  is a exemplary view illustrating various examples of a bending portion  40 , where “A” shows the bending portion formed by a groove (U) concaved in the plate before and after the plate is diagonally bent and “B” shows the bending portion formed by dividing the plate along a section boundary and coupling the divided plates by a bending portion   (T) and “C” shows the bending portion formed by a groove (H) perforated in the plate; 
         FIG. 13  is a plan view illustrating a plate provided with the bending portion of “C” of  FIG. 12 ; 
         FIG. 14  is a view illustrating side and bottom of a wheel  20  according to one embodiment; and 
         FIG. 15  is a front view illustrating turning operations of the wheel when the wheel of  FIG. 14  is mounted on the bottom of the plate and the plate is diagonally bent, where “A” shows operation of a front wheel and “B” shows operation of a rear wheel through cutting the middle portion of the plate. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     Referring to  FIGS. 1 to 3 , a skateboard according to one embodiment of the present invention includes: a plate  10  that can be divided into a first side  11 , a second side  12 , a third side  13  and a fourth side  14  along section boundaries C 1  and C 2  formed when the plate is diagonally bent; a supporting unit  30  ( 30 L,  30 R) provided at the third and fourth sides  13  and  14  of the plate  10  in order to prevent them from being bent; and a wheel unit  20  having driving wheels (W) provided at the first and second sides  11  and  12  of the plate  10 . 
     It is desirable that the plate  10  is made of elastic material such as bendable flexible, thermoplastic or elastic rubber, metal, synthetic resin, PE which has strength to endure load of a user and can be easily elastically restored after the first and second sides  11  and  12  are diagonally bent so as to cross each other. 
     The first and fourth sides  11  and  14  form a triangle shape. As shown in  FIG. 3 , the first and fourth sides  11  and  14  are paired with each other and the second and third sides  12  and  13  are paired with each other according to the bending direction. The first and fourth sides  11  and  14  and second and third sides  12  and  13  can be bent along the section boundary C 1  between them. When the plate is bent oppositely to the above bending direction, the first and third sides  11  and  13  are paired with each other and the second and fourth sides  12  and  14  are paired with each other. The first and third sides  11  and  13  and second and fourth sides  12  and  14  can be bent along the section boundary C 2  between them. 
     Accordingly, the first and second sides  11  and  12  of the plate  10  can be inclined to the left or right according to the bending direction. 
     On the other hand, the middle portion of the plate  10  may be bent by the load of the user. To solve the problem, the supporting unit  30  ( 30 L,  30 R) are provided at the third and fourth sides  13  and  14  of the plate  10  in order to prevent the middle portion from being bent. 
     The supporting unit  30  may be a supporting shaft made of metal or synthetic resin that is formed or coupled along a length of the plate  10  or a supporting plate that is additionally attached to the surface of the plate  10 . 
     Referring to  FIGS. 2 and 5A , the supporting shaft is attached to edges of the third and fourth sides  13  and  14  in a shape of rod. In addition, referring to  FIGS. 4A and 4D , the supporting shaft is additionally attached.  FIGS. 4E and 4F  show supporting shafts formed by vertically folding, projecting or thickening the edges of the plate  10 . Of course, the supporting shaft may not be provided at the outermost edge but provided near the middle of the plate  10  within the range in which the middle portion of the plate is not bent. 
     The supporting plate may be additionally attached to the third and fourth sides  13  and  14  of the plate  10  as shown in  FIG. 5B . In addition, the supporting plate may be attached to the first and second sides  11  and  12  in order to help the plate to bear the load of the user better. 
     On the other hand, the supporting shaft may be also additionally provided at the first and second sides  11  and  12 . 
     The wheel unit  20  may include at least one caster wheel that can turn according to inclination of the plate  10 . Particularly, as shown in  FIG. 14 , the caster may be a direction-caster whose bracket (B) is pivoted (P) to a  20 P fixing the wheel unit  20  on the bottom of the plate  10  with a wedge angle (A) to a running direction. In addition, the wheel unit  20  may include a truck instead of the caster wherein the truck is a driving unit used in the conventional skateboard. In addition, the driving unit may be formed by properly combining the caster, truck or fixed wheel set to each other. 
     Referring to  FIG. 15 , the direction-caster is turned in proportional to horizontal inclination of the plate  10  to generate driving force.  FIG. 15A  shows the turning operation (DF) of a front wheel  20 F of the wheel unit  20  according to inclination of the plate  10  and  FIG. 15B  shows the turning operation (DR) of a rear wheel  20 R of the wheel unit  20 . 
     As described above, the skateboard can be steered with a very short turning radius and can generate driving force. 
     Mode for the Invention 
       FIGS. 6 to 9  show various embodiments of the supporting unit  30 . 
     Referring to  FIG. 6 , the supporting shaft is formed by vertically folding or projecting the first to fourth edges of the plate. The plate cannot be bent in other directions except that the plate is diagonally bent along the section boundaries C 1  and C 2 . Referring to  FIG. 7 , a plurality of supporting shafts used in the supporting unit  30  are formed to bear heavy load. Referring to  FIG. 8 , a reinforcing support unit (EF) is projected vertically from the entire plate so as to bear heavy load. Referring to  FIG. 9 , the supporting shaft or reinforcing support units are formed on the plate except for the section boundaries C 1  and C 2 . 
     The plates  10  shown in  FIGS. 10 ,  11  and  12 B are hard or not easily bent. The plate  10  is divided into segments such as a first side  11 , a second side  12 , a third side  13  and fourth side  14  and the section boundaries C 1  and C 2  between the segments are coupled by bending portion  40  ( 41 ,  42 ). A bendable member (T) such as rubber or metal is used as the bending portion  40 . It is more desirable that the bending portion is elastically restorable. 
     As shown in  FIGS. 12A ,  12 C and  13 , the plate  10  itself is not easily bent but bendable through the bending portion  40  formed by a concaved groove (U) or perforated groove (H). 
     INDUSTRIAL APPLICABILITY 
     The skateboard of the present invention can be used in wheel reports fields such as play, performance and driving using the same.