SKATEBOARD
A body 11 that constitutes a skateboard is formed into a U shape with bases of a pair of plate-like legs 14, 15 being integrated, and end portions 17, 18 of the legs 14, 15 are relatively displaceable in a thickness direction by elasticity of the body 11. The end portions 17, 18 of the legs 14, 15 are coupled by a coupling member 19. One wheel 12 is provided on a lower surface of an integral portion 16 at the base ends, and the other wheel 13 is provided on a lower surface of the coupling member 19. The step board 41 is placed between the end portions 17, 18 of the legs 14, 15, and has contact portions 46, 53 that come into contact with the legs 14, 15 by following displacement of the end portions 17, 18 of the legs 14, 15 in the thickness direction.
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The present invention relates to a skateboard, and more particularly to a skateboard including casters swingable around an inclined pivot as traveling wheels.
BACKGROUND OF THE INVENTIONAs such a skateboard, WO2007/127554 describes a skateboard having a one piece body made of a material twistable around a front-back axis. This body includes a pair of front and rear foot support areas, and a central section between the foot support areas. The central section is narrower than the foot support regions so as to twist the body.
With such a configuration, a user on a traveling skateboard can adjust forces applied to the body from the feet on the foot support regions to twist the body as described above. When the body is twisted, a front caster provided on a lower surface of a front foot support area and a rear caster provided on a lower surface of a rear foot support area are swingable around an inclined central axis, and thus turn in opposite lateral directions. This causes the skateboard to travel in a serpentine manner, and a component of force at that time generates forward propulsion. Thus, the skateboard travels by itself simply by the user twisting the body without additionally pushing off on the ground.
DISCLOSURE OF THE INVENTIONHowever, in order to sufficiently turn the front and rear casters in the opposite lateral directions, the body needs to be significantly twisted. Thus, large forces need to be applied from the feet to the body. Thus, the skateboard does not have sufficient operability.
Therefore, the present invention has an object to solve such a problem and allow casters having an inclined central axis to be sufficiently laterally swingable even if a user on a skateboard applies small forces.
To achieve this object, the present invention provides a skateboard including: a body; wheels at front and rear of a lower surface of the body; a coupling member; and a step board, wherein the wheels are constituted by swingable casters having an inclined pivot, the body is formed into a U shape with bases of a pair of plate-like legs being integrated, end portions of the pair of legs are relatively displaceable in a thickness direction thereof by elasticity of the body, the end portions of the pair of legs are coupled by the coupling member so as to be displaceable in the thickness direction, one of the swingable casters is provided on a lower surface of the integrated bases of the pair of legs, the other of the swingable casters is provided on a lower surface of the coupling member, and the step board is placed between the end portions of the pair of legs and has a contact portion that comes into contact with the legs by following displacement of the end portions of the legs in the thickness direction.
According to the present invention, the body is constituted by a U-shaped member with the bases of the pair of plate-like legs being integrated, the end portions of the pair of legs are coupled by the coupling member so as to be displaceable in the thickness direction by the elasticity of the body, and the swingable caster is provided on the lower surface of the coupling member. Thus, when the end portions of the pair of legs are displaced in the thickness direction, the coupling member is inclined according to the displacement of the legs. Then, the caster provided on the coupling member swings around the inclined pivot, and is thus significantly turned according to an inclination of the coupling member.
Specifically, according to the present invention, the end portions of the pair of plate-like legs that constitute the U-shaped body are relatively deformed with small forces in the thickness direction by the elasticity of the body, and thus the coupling member can be inclined between the legs, and the inclination allows the caster to be sufficiently turned.
Further, according to the present invention, the step board having the contact portion that comes into contact with the pair of legs according to the displacement of the end portions of the legs in the thickness direction is placed between the end portions of the legs. Thus, in positions of the end portions of the legs, a complex configuration is provided in which the pair of legs and the coupling member are provided and the legs are coupled by the coupling member, and a complex operation based on the configuration is performed. Nevertheless, an operator can stably place the foot on the step board, and can easily operate the skateboard.
As shown in
The body 11 has a U shape on plan view, and includes a pair of legs 14, 15 that form the U shape and have a predetermined width. Reference numeral 16 denotes an integral portion at which bases of the legs 14, 15 are integrated, which forms a curved portion of the U shape. Reference numerals 17 and 18 denote end portions of the legs 14, 15. The body 11 may include the integral portion 16 at which the bases of the pair of legs 14, 15 are integrated, and the end portions 17, 18 of the legs 14, spaced apart, and thus need not have an exact U shape. For example, the body 11 may have a V shape or other shapes, and such shapes are generally referred to as “U shape” in the present invention.
In the body 11, the end portions 17, 18 of the pair of legs 14, 15 are relatively displaceable in a thickness direction by elasticity of the body 11 as described later in detail. The body 11 may be made of plate-like synthetic resin so as to be elastically displaceable. Alternatively, the body 11 may be made of wood, light metal, composite materials, or the like.
A coupling member 19 is placed between inner edges of the legs 14, 15 in the end portions 17, 18. In an example in
Front and rear sides of the skateboard in
As shown in
As shown in
The coupling member 19 includes a mounting shaft 43. The mounting shaft 43 is placed horizontally in the longitudinal direction, that is, a front-back direction of the body 11. In the shown example, a base portion of the mounting shaft 43 is mounted to the coupling member 19, and an end portion thereof protrudes from the coupling member 19 toward a rear end of the body 11. The protruding end portion of the mounting shaft 43 extends through the brackets 42, 42. The brackets 42, 42 have through holes 44, 44 through which the mounting shaft 43 extends. The through holes 44, 44 are formed as slots in a displacement direction of the end portions 17, 18 of the legs 14, 15, that is, in a thickness direction of the legs 14, 15. A separation preventing member 45 such as a nut for preventing the step board 41 from being separated from the mounting shaft 43 is fitted to a portion of the mounting shaft 43 protruding from the rear bracket 42. Thus, in the shown example, the step board 41 is located immediately above the rear wheel 13 when the rear wheel 13 can roll in the longitudinal direction of the skateboard on the rear side of the pivot 24 as described above.
Contact surfaces 47, 47 for supporting a flat lower surface 46 as a contact portion of the step board 41 are formed on upper surfaces of the end portions 17, 18 of the legs 14, 15 of the body 11. Each contact surface 47 has a curved surface that can come into linear contact with the lower surface 46 of the step board 41 in the longitudinal direction, that is, the front-back direction of the body 11. Such a curved surface is, for example, a cylindrical surface having a central axis in the longitudinal direction of the body 11. To form the contact surfaces 47, 47, protrusions 48, 48 are formed on the upper surfaces of the end portions 17, 18 of the legs 14, 15 integrally with or separately from the legs 14, 15. Alternatively, the upper surfaces of the legs 14, 15 may be formed to be flat, and a protrusion 48 having a curved contact surface 47 may be formed on the step board 41. Further, protrusions 48 each having a curved contact surface 47 may be formed on both the legs 14, 15 and the step board 41.
As shown in
An operation of the skateboard will be described. Only the plate-like body 11 of the skateboard in
The legs 14, 15 can be displaced by elasticity of the body 11 by the operator operating the step board 41 using the foot on the step board 41. Specifically, if the operator places the weight on a side of the step board 41 corresponding to one of the legs 14, 15, the one leg on which the weight is placed is displaced downward from the other leg. At this time, the step board 41 follows relative displacement of the legs 14, 15 in the thickness direction, and is inclined around the mounting shaft 43. Then, the step board 41 is loosely coupled to the mounting shaft 43 via the through holes 44 constituted by the slots. Also, the contact surfaces 47 of the protrusions 48 on the legs 14, 15 have the curved surfaces such as cylindrical surfaces having a central axis in the longitudinal direction of the body 11. Thus, even if the legs 14, 15 are relatively displaced in the thickness direction, the step board 41 can always follow the displacement in contact with the contact surfaces 47.
For a relationship between the mounting shaft 43, the step board 41, and the contact surfaces 47, the lower surface 46 of the step board 41 may be always in contact with the contact surfaces 47 irrespective of a relative displacement amount of the legs 14, 15 in the thickness direction and an inclination of the step board 41 according to the displacement amount. For this purpose, as described above, it is effective that the through holes 44 in the brackets 42 of the step board 41 are formed as slots in the thickness direction of the legs 14, 15, and the contact surface 47 is the cylindrical surface having the central axis in the longitudinal direction of the body 11. Other configurations may be used.
As shown in
In this state, for example, as shown in
At this time, the coupling member 19 is inclined between the inner edges of the left and right legs 14, 15 using the hinges 20, 20. Thus, the coupling member 19 can be significantly inclined depending on a difference in height between the end portions 17, 18 of the legs 14, 15, thereby causing the wheel 13 with a caster structure to swing with a large angle. At this time, in the shown example, the step board 41 is placed immediately above the rear wheel 13 as described above, thereby causing the wheel 13 to swing with a smaller force than when the step board 41 is placed in a different place. As described later, of course, a configuration may be used in which the step board 41 is placed in a position other than immediately above the rear wheel 13.
Specifically, as shown in
At this time, the step board 41 is placed immediately above the rear wheel 13 as in the shown example to allow the wheel 13 to be turned with a small force, thereby allowing the skateboard to be turned with extremely high operability.
As shown in
Thus, the body 11 turns to the right. If the forces applied to the body 11 from the front and rear feet are reversed during the turn, the front and rear wheels 12, 13 swing in the directions opposite to the above. Further, an operation of reversing the forces applied to the body 11 from the front and rear feet is repeated to cause the body 11, that is, the skateboard to travel in a serpentine manner with a wave-shaped path 21. At this time, as shown in
In the operation in
The operation at this time may be performed by the foot on the step board 41. Thus, in the positions of the end portions 17, 18 of the legs 14, 15, a complex configuration is provided in which the pair of legs 14, 15 and the coupling member 19 are provided and the legs 14, 15 are coupled by the coupling member 19, and a complex operation based on the configuration is performed. Nevertheless, the operator can stably place the foot on the step board 41, and can easily operate the skateboard.
Specifically, as shown in
The step board 41 of the skateboard in
To address such a situation, in the step board 41 in
At this time, the end portion of each elastic tongue 53 presses the protrusion 48 of the step board 41, and thus the step board 41 is lifted from the legs 14, 15 by reaction, and stabilized with a bottom edge of the through hole 44 being pressed against the mounting shaft 43. Thus, the step board 41 does not freely move with respect to the mounting shaft 43 and the legs 14, 15, and is thus stabilized, and collision between members can be prevented.
In the shown example, the pair of elastic tongues 53, 53 is provided for each protrusion 48 of the legs 14, 15, but any configuration may be used. For example, a single elastic tongue 53 may be provided for each protrusion 48. Instead of the elastic tongue 53, the protrusions 48, that is, the legs 14, 15 may be formed of elastic bodies that can be pressed. The elasticity bodies may be formed integrally with the step board 41 as described above, or separately formed. In the shown example, the size of the elastic tongue 53 in the front-back direction of the skateboard, that is, the size of the elastic tongue 53 in a direction perpendicular to the sheet surface of
In this configuration, for example, when the skateboard is not used, the projection 57 of the step board 41 is regulated by the torsion coil spring 54 to prevent the step board 41 from freely oscillating or turning around the mounting shaft 43. This advantageously allows the step board 41 having the contact portion lifted from the contact surfaces 47, 47 of the legs 14, to be stably kept with respect to the legs 14, 15, and prevents collision between the members.
When the legs 14, 15 are relatively displaced in the thickness direction of the skateboard by the step board 41 during the operation of the skateboard, the step board 41 may be strongly turned around the mounting shaft 43 against a spring force of the torsion coil spring 54.
When the body 11 is made of synthetic resin, the balls 34, 34 are firmly pressed into the recesses 35, 35 to elastically deform the resin around the recesses 35, 35, and thus can be fitted into the recesses 35, 35. Although not shown, protruding stoppers are preferably formed on inner surfaces of the recesses 35, 35 so that the balls 34, 34 can be easily fitted into the recesses 35, 35, but are hard to be removed from the recesses 35, 35. Such stoppers may be protrusions having a gentle inclination in a fitting direction of the balls 34, 34 but having a steep inclination in a removing direction. In this case, the balls may be made of any material, but for example, the coupling member 19 and the balls 34, 34 are preferably made of the same resin as the body 11.
As such, when the legs 14, 15 and the coupling member 19 are coupled by the ball joints 33, a coupling portion may have increased flexibility as compared to the coupling structure using the hinges 20, 20 described above. Thus, the coupling portion can address a case where the legs 14, 15 of the body 11 are displaced in the thickness direction, and also a case where the legs 14, of the body 11 are relatively displaced in other complex directions.
With such a configuration, the thin portions 37 having the grooves 38 formed on both the upper and lower surfaces of the legs 14, 15 and the coupling member 19 may have the same function as the hinges 20 described above. Thus, similarly, the end portions 17, 18 of the legs 14, 15 can be relatively displaced in the thickness direction. In this case, the legs 14, 15 and the coupling member 19 are repeatedly elastically deformed to be bent, and thus the body 11 and the coupling member 19 including the thin portions 37 need to be made of a synthetic resin material so as to resist such repeated deformation. In this case, the thin portion 37 is made of elastically deformable resin, and thus can address a case where the legs 14, 15 are displaced in the thickness direction by elasticity of the body 11, and also a case where the legs 14, 15 are displaced in other complex directions. Further, with this configuration, the legs 14, 15 and the coupling member 19 are integrally formed via the thin portion 37, thereby reducing the number of components as compared to the case where the legs 14, 15 and the coupling member 19 are separately formed.
According to the present invention, the coupling structure between the legs 14, 15 and the coupling member 19 is not limited to the example described above, but any configuration may be used as long as the legs 14, 15 and the coupling member 19 are coupled so that the legs 14, are displaceable in the thickness direction by the elasticity of the body 11.
Claims
1. A skateboard comprising:
- a body;
- wheels at front and rear of a lower surface of the body;
- a coupling member; and
- a step board,
- wherein the wheels are constituted by swingable casters having an inclined pivot,
- the body is formed into a U shape with bases of a pair of plate-like legs being integrated, end portions of the pair of legs are relatively displaceable in a thickness direction thereof by elasticity of the body, the end portions of the pair of legs are coupled by the coupling member so as to be displaceable in the thickness direction,
- one of the swingable casters is provided on a lower surface of the integrated bases of the pair of legs, the other of the swingable casters is provided on a lower surface of the coupling member, and
- the step board is placed between the end portions of the pair of legs and has a contact portion that comes into contact with the legs by following displacement of the end portions of the legs in the thickness direction.
2. The skateboard according to claim 1, wherein the step board is mounted to the coupling member.
3. The skateboard according to claim 1, wherein the step board is pivotable around an axis in a front-back direction of the skateboard, the end portions of the pair of legs have contact surfaces with which the contact portion of the step board comes into contact by following displacement of the end portions of the legs in the thickness direction, and at least one of the contact surfaces of the legs and the contact portion of the step board has a curved surface.
4. The skateboard according to claim 1, wherein the coupling member and one and the other legs are coupled by hinges.
5. The skateboard according to claim 3, wherein the contact portion of the step board is pressed against the contact surfaces of the legs by spring elasticity.
6. The skateboard according to claim 3, further comprising a holding member for holding the step board in a certain position when the contact portion of the step board moves from the contact surfaces of the legs.
Type: Application
Filed: Feb 26, 2013
Publication Date: Oct 24, 2013
Applicant: J.D. JAPAN CO., LTD. (Osaka)
Inventor: Hideyasu Yamabe (Osaka)
Application Number: 13/777,292
International Classification: A63C 17/01 (20060101); A63C 17/00 (20060101);