Description

SKATEBOARD HAVING GOOD PROPERTY IN TORSION AND BENDING

Technical Field

[1] The present invention relates, in general, to skateboards and, more particularly, to a skateboard having good torsion and bending properties.

Background Art [2] Generally, a skateboard is a board with wheels, which is ridden down a slope or the like, with a rider putting two feet on the skateboard. The skateboard includes two pairs of wheels which are attached to the underside of a track- shaped plate in such a way as to be spaced apart from each other by a predetermined distance. [3] In order to move the skateboard forwards or backwards, a user must push his or her foot against the ground. Further, in order to perform a turning action, the skateboard must be tilted to a side so that the turning radius is increased. [4] A skateboard for solving the problem is disclosed in Korean U.M. Registration No.

20-0410530. [5] As shown in FIGS. 8 and 9, a conventional skateboard includes one plate 18, 19,

600, a pair of wheel supports 300, and a pair of wheels 200. [6] One plate 18, 19, 600 has a planar shape, and includes wide portions 18 and 19 and a narrow portion 600 which are coupled to each other to form a single structure. A rider's feet are placed on the wide portions 18 and 19. The narrow portion 600 is twisted or bent relative to the wide portions 18 and 19. A movable shaft 640 is provided in the plate 18, 19, 600 in such a way as to extend from the narrow portion

600 to predetermined positions. [7] The wheel supports 300 are mounted, respectively, to the undersides of the wide portions 18 and 19 of the plate. [8] The wheels 200 are secured to the corresponding wheel supports via directional casters which are provided on the inclined surfaces of the wheel supports 300. [9] Such a skateboard moves in an S-shape and obtains a thrusting force not by the ground being pushing by a user's foot but by the mere twisting of his or her body.

Because of the bending motion during riding, the skateboard can easily be turned even in areas of a small radius. [10] However, since such a conventional skateboard is constructed so that the wheel supports are directly coupled to a plate which is made of an elastic synthetic resin, the

coupled portions may be damaged when shocks are applied to the plate.

[11] Further, when the coupled portions become damaged, it is difficult to repair just a part of the plate, so that the entire plate must be replaced with a new one, and thus the financial burden is large.

[12] Further, the narrow portion of the plate may be excessively bent vertically as well as horizontally, thus causing the sudden stopping of the plate during riding, and causing a user to fall off the skateboard. Disclosure of Invention Technical Problem

[13] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a skateboard, in which a wheel assembly is indirectly coupled to one plate having elasticity via a wheel-assembly mounting plate, so that there is little possibility of damage to the plate even if shocks are applied thereto.

[14] Another object of the present invention is to provide a skateboard, which enables the replacement of only a damaged part from among several parts including a plate, a footboard, or a wheel-assembly mounting plate, when the parts are damaged by shocks, thus lessening the financial burden.

[15] A further object of the present invention is to provide a skateboard, in which an elastic piece is attached to a coupler, so that the skateboard is easily bent leftwards or rightwards but is not easily bent upwards or downwards, thus preventing the sudden stopping of a plate during riding, and preventing a user from falling off the skateboard. Technical Solution

[16] In order to accomplish the above objects, the present invention provides a skateboard having good torsion and bending properties, including a pair of footboards for supporting a user's feet, one plate for coupling the pair of footboards to each other in such a way that the footboards are freely twistable and bendable relative to each other, a wheel assembly for generating propulsive force by movement of the user's body or feet, and a pair of wheel-assembly mounting plates for mounting the wheel assembly to the plate.

[17] The skateboard further includes a pair of cover plates for protecting the pair of footboards from an exterior.

[18] The pair of cover plates is removably coupled to the corresponding footboards using a hook.

[19] One plate includes a pair of footboard base plates on which the corresponding footboards are mounted, and a coupler for coupling the footboard base plates to each other, the pair of footboard base plates being twisted and bent relative to the coupler.

[20] An elastic piece is mounted to the coupler to allow the pair of footboard base plates to be smoothly twisted relative to each other and bent horizontally, but suppresses vertical bending.

[21] The elastic piece is inserted into an insert groove formed in the coupler, and is removably fastened to the coupler via a bolt.

[22] The elastic piece has an arch shape or a U shape, and includes an arch section inserted into the insert groove, and a flat section fastened to the coupler via a bolt.

[23] In the skateboard of the present invention, the plate is made of ethylene propylene rubber.

[24] The ethylene propylene rubber has an intensity from 80°to 90°.

[25] Each of the wheel-assembly mounting plates is provided with a wedge having an inclined surface so as to obliquely mount the wheel assembly.

[26] The wheel assembly includes a caster which is removably fastened to the wedge, and a wheel which is rotatably coupled to the caster.

[27] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings. Here, the terminologies or words used in the description and the claims of the present invention should not be interpreted as being limited merely to common and dictionary meanings, but should be interpreted based on the meanings and concepts of the invention in keeping with the scope of the invention on the basis of the principle that the inventor can appropriately define the terms in order to describe the invention in the best way.

Advantageous Effects

[28] As described above, a skateboard according to the present invention is advantageous in that a wheel assembly is indirectly coupled to one plate having elasticity via a wheel-assembly mounting plate, so that there is little possibility of damage to the plate even if shocks are applied thereto.

[29] Further, a skateboard according to the present invention is advantageous in that it enables the replacement of only a damaged part from among several parts including a plate, a footboard, or a wheel-assembly mounting plate, when the parts are damaged by shocks, thus lessening the financial burden.

[30] Furthermore, a skateboard according to the present invention is advantageous in that

an elastic piece is attached to a coupler, so that the skateboard is easily bent leftwards or rightwards but is not easily bent upwards or downwards, thus preventing the sudden stopping of a plate during riding, and preventing a user from falling off the skateboard.

Brief Description of the Drawings [31] HG. 1 is a schematic exploded perspective view illustrating a skateboard according to the preferred embodiment of the present invention; [32] HG. 2 is a side view illustrating the skateboard of HG. 1 ;

[33] HG. 3 is a schematic view illustrating the skateboard of HG. 1;

[34] HG. 4 is a schematic enlarged view illustrating a coupler of HG. 1 ;

[35] HG. 5 is a schematic view illustrating the operation of the skateboard of HG. 1;

[36] HG. 6 is a schematic view illustrating the state in which the skateboard of HG. 1 is excessively bent downwards relative to footboards; [37] HG. 7 is a schematic view illustrating the state in which the skateboard of HG. 1 is excessively bent upwards relative to the footboards; [38] HG. 8 is a schematic view of a conventional skateboard; and

[39] HG. 9 is a side view illustrating the skateboard of HG. 8.

[40] ( Description of reference characters of important parts )

[41] 100 : skateboard 110 : plate

[42] 120 : footboard 130 : cover plate

[43] 140 : wheel-assembly mounting plate

[44] 150 : wheel assembly

Mode for the Invention [45] The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description. [46] Hereinafter, a skateboard having an advertising function according to the present invention will be described with reference to the accompanying drawings. [47] Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components. For the clarity of description, known functions and constructions relating to the present invention will be omitted herein. [48] HG. 1 is a schematic exploded perspective view illustrating a skateboard according to the preferred embodiment of the present invention, HG. 2 is a side view illustrating the skateboard of HG. 1, HG. 3 is a schematic view illustrating the skateboard of HG.

1, and HG. 4 is a schematic enlarged view illustrating a coupler of HG. 1.

[49] As shown in HGS. 1 to 4, the skateboard 100 according to this embodiment includes one plate 110, a pair of footboards 120, a pair of cover plates 130, a pair of wheel- assembly mounting plates 140, and four wheel assemblies 150.

[50] One plate 110 functions to oouple the pair of footboards 120 to each other such that the positions of the footboards may be changed relative to each other. The plate includes two footboard base plates 111 and one coupler 112, and is made of a rubber material.

[51] The plate 110 may be manufactured using natural rubber, butadiene rubber, ethylene propylene rubber, or other rubbers.

[52] Here, the natural rubber has superior elasticity, abrasion resistance, and low- temperature hardiness, although it has poor oil resistance, heat resistance, weather resistance, and o»ne resistance, so that it is unsuitable for using outdoors or in a place with strong sunlight. The butadiene rubber has superior elasticity, abrasion resistance, low-temperature hardiness, and generates a small amount of heat, although it exhibits poor mechanical characteristics and difficulty of processing, so that manufacturing costs are increased. The ethylene propylene rubber exhibits superior elasticity, weather resistance, heat resistance, and o»ne resistance, and in addition, has very superior ease of processing. Thus, in this embodiment, the plate 110 is made of ethylene propylene rubber.

[53] The intensity of the ethylene propylene rubber is adjusted by mixing an additive with the ethylene propylene rubber, so that the balance, restoring force, and tensile force of the ethylene propylene rubber can be adjusted. If the intensity of the ethylene propylene rubber is high, the restoring force is reduced. In contrast, if the intensity is low, the restoring force is increased, but the ethylene propylene rubber becomes excessively malleable, so that it is difficult to maintain the shape of the skateboard. It is preferable that the rubber have an intensity from 80°to 90°.

[54] Each footboard base plate 111 has an elliptical edge 113 and an extension 114 which extends from the edge 113 in such a way as to form a step. The edge 113 is rounded, and a plurality of through holes 115 is formed in the extension 114 at regular intervals.

[55] The coupler 112 is an arc- or U-shaped, and has a thickness from 2cm to 3cm and a width of 4cm. A pair of arc- or U-shaped insert grooves 116 is provided in the lower portion of the coupler 112, and an elastic piece 160 having a predetermined rigidity is inserted into the insert grooves 116.

[56] The elastic piece 160 includes arch sections 161 which are inserted into the insert grooves 116, and flat sections 162 which are fastened to a plurality of bolts 117

protruding from the coupler 112. A plurality of through holes 163 is formed in the flat sections 162 such that the plurality of bolts 117 passes through the through holes. The elastic piece 160 allows the coupler 112 to bend freely in a hori»ntal direction, but prevents the coupler from bending in a vertical direction. The degree or extent of bending may be changed depending on the rigidity of the elastic piece 160.

[57] A pair of footboards 120 functions to support a user's feet. Each footboard is inserted into the corresponding edge 113 in such a way as to be placed on the extension 114 of the footboard base plate 111.

[58] A plurality of through holes 121 is formed in each footboard 120 to correspond to the plurality of through holes 115 which are formed in the extension 114, and a plurality of fastening holes 122 is formed between the through holes 121.

[59] A pair of cover plates 130 serves to protect the footboards 120 from the exterior, and a plurality of hooks 131 is on the underside of each cover plate which are to be fitted into the corresponding fastening holes 122.

[60] For purposes of selling, a trademark or a design preferred by consumers may be printed on each cover plate 130, and may be easily replaced with another one.

[61] A pair of wheel- assembly mounting plates 140 is used to mount the wheel assemblies

150 to the plate 110, and has the same size and shape as the footboard base plates 111.

[62] A plurality of through holes 141 is formed in each wheel- assembly mounting plate

140 to correspond to the through holes 121 formed in each footboard 120. Further, wedges 142 are provided on each wheel-assembly mounting plate in such a way that the wedges are aligned in the same line and are spaced apart from each other by a predetermined interval, and the wheel assemblies 150 are removably mounted to the wedges. Each wedge 142 has an inclined surface 143 which is in contact with each wheel assembly 150, with a fastening depression 145 formed in the inclined surface 143 so that a bolt 144 is fastened to the fastening depression.

[63] Four wheel assemblies 150 are used to propel the skateboard by the movement of a user's body or feet. Each wheel assembly includes a caster 151 and a wheel 152.

[64] A through hole 153 is formed in the caster 151 so that the caster is fastened to the corresponding wedge 142 using the bolt 144, and a fork 154 is provided on the caster to hold the corresponding wheel 152. Each caster 151 may freely rotate axially around the corresponding bolt 144.

[65] Each wheel 152 is coupled to the fork 154 in such a way as to freely rotate around an axis.

[66] The skateboard 100 having the above-mentioned construction is assembled as

follows.

[67] First, each footboard 120 is placed on the upper surface of the extension 114 which is provided on the corresponding footboard base plate 111 of the plate 110.

[68] Next, each wheel-assembly mounting plate 140 is attached to the lower surface of the extension 114 which is provided on the corresponding footboard base plate 111 of the plate 110.

[69] Subsequently, a plurality of bolts 118 passes through the through hole 121, 115, and

141 which are formed in the corresponding footboard 120, extension 114, and wheel- assembly mounting plate 140, and is tightened by nuts 119 so that the parts are assembled to each other.

[70] Thereafter, each caster 151 equipped with the wheel 152 is secured to the corresponding wedge 142 of each wheel-assembly mounting plate 140 using the bolt 144.

[71] The operation of the skateboard 100 according to this embodiment will be described with reference to FlG. 5.

[72] As shown in FIG. 5, the skateboard 100 can be moved in the directions shown by the dotted lines, by the movement of a user's body or feet.

[73] For example, when the left side of the skateboard 100 is moved in the direction shown by arrow A and the right side is moved in the direction shown by arrow B, the skateboard 100 is bent into a V shape. Meanwhile, when the left side of the skateboard 100 is moved in the direction shown by arrow C and the right side is moved in the direction shown by arrow D, the skateboard 100 is bent into a λ shape. Further, when the left side of the skateboard 100 is moved in the direction shown by arrow A and the right side is moved in the direction shown by arrow D, or when the left side is moved in the direction shown by arrow C and the right side is moved in the direction shown by arrow B, the skateboard 100 assumes the shape of an S.

[74] As such, through the movement of a user's body or feet, the skateboard 100 is moved in the shape of a V, a λ, an S, or combinations thereof. Thus, the skateboard can be propelled in a desired direction without the ground being pushed against by a user's foot.

[75] Further, even when the skateboard 100 is displaced by the movement of a user's body or feet, the elastic piece 160 mounted to the coupler 112 prevents the skateboard from being bent excessively downwards as shown in FIG. 6 or from being bent excessively upwards as shown in FIG. 7.

[76] Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications,

additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.