WO2008130098A1

WO2008130098A1 - Front wheel steering apparatus

Info

Publication number: WO2008130098A1
Application number: PCT/KR2008/001137
Authority: WO
Inventors: Ho Seong Choi
Original assignee: Individual
Current assignee: Individual
Priority date: 2007-04-23
Filing date: 2008-02-27
Publication date: 2008-10-30
Anticipated expiration: 2009-10-23

Abstract

Disclosed herein is a front wheel steering device. The front wheel steering device includes a handle, a steering shaft, a bearing member, and a horizontal frame. The handle is manipulated by a driver. The steering shaft is configured such that one end thereof is coupled to the lower end of the central portion of the handle and extends downwards from the lower end. The bearing member is configured such that the steering shaft is coupled to the inner side of the bearing member. In this case, the bearing member supports the steering shaft so that the steering shaft 110 is rotated around an axis or is inclined in multiple directions. The horizontal frame is configured such that one end thereof is coupled to the bearing member to form a predetermined angle with the steering shaft.

Description

FRONT WHEEL STEERING APPARATUS

Technical Field

[1] The present invention relates to a front wheel steering device and, more particularly, to a front wheel steering device, which, when a driver drives a vehicle having a single front wheel, such as a bicycle or a motorcycle, enables the front wheel to be steered according to the manipulation of a handle. Background Art

[2] Generally, in a conventional front wheel steering device, which is used for a vehicle having a single front wheel, such as a bicycle or a motorcycle, the driving direction of the vehicle is determined only by the left and right rotation of the apparatus, which is effected by the manipulation of a handle.

[3] Accordingly, a bicycle or like, having the conventional front wheel steering device, described above, is problematic in that, when turning is conducted, it is difficult to achieve smooth cornering if a driver does not tilt his or her body to conform to the movement of the center of a vehicle body, and additionally in that, when an obstruction appears suddenly, it is difficult to avoid the obstruction because the rotation radius is large.

[4] In Korean Unexamined Utility Model Publication No. 2000-0002228, entitled

"Three- wheeled Vehicle Capable of Being Easily Turned," a three- wheeled vehicle, having a steering device, which can not only be rotated in the left and right directions so that turning can be easily performed, but can also be restored to the original position when the vehicle is inclined in the left and right direction, is disclosed.

[5] However, the conventional technology is disadvantageous in that smoothly connected motions cannot be performed in the case where rotation and inclination occur simultaneously because the center of rotation does not coincide with the center of inclination, unlike the case where the center of rotation coincides with the center of inclination.

[6] Furthermore, in existing bicycles, horizontal frames are each integrally formed in order to maintain stability during traveling, whereas, in a conventional three- wheeled vehicle, a horizontal frame is divided into parts. However, in a conventional three- wheeled vehicle, the driver may be in a relatively unstable state because torsion action occurs in the horizontal frame when the steering device is rotated, the user may be soiled by, for example, lubricant, because the portions in which the torsion action occurs are close to the user, the division parts may frequently break down due to the center of gravity of the driver, and the merchantable value is lowered from the point of view of design.

[7] In addition, as to the construction that enables restoration when rotation and inclination occur, the conventional three- wheeled vehicle is characterized in that an extension spring is externally formed. However, there are problems in that this makes the outward appearance complicated, and in that safety cannot be ensured because the extension spring may cause the driver to fall. Disclosure of Invention Technical Problem

[8] 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 front wheel steering device, which enables inclination as well as rotation using a simple structure, thus improving cornering and riding.

[9] Another object of the present invention is to provide a front wheel steering device, which enables the angle between a steering shaft and a horizontal frame to be changed and fixed, thus facilitating change to a structure suitable for traveling conditions.

[10] A further object of the present invention is to provide a front wheel steering device, which is provided with an elastic member, so that it enables the steering shaft to be restored to its original position using elasticity when the steering shaft is rotated or inclined, thus increasing convenience for drivers.

[11] The other objects and advantages of the present invention will be described below, and will be understood from embodiments of the present invention. Furthermore, the objects and advantages of the present invention may be realized using means which are described in the claims, and a combination thereof. Technical Solution

[12] In order to accomplish the above objects, the present invention provides a front wheel steering device, including: a handle manipulated by a driver; a steering shaft configured such that one end thereof is coupled to the lower end of the central portion of the handle and extends downwards from the lower end; a bearing member configured such that the steering shaft is coupled to the inner side of the bearing member, the bearing member supporting the steering shaft so that the steering shaft 110 is rotated around an axis or is inclined in multiple directions; and a horizontal frame configured such that one end thereof is coupled to the bearing member to form a predetermined angle with the steering shaft.

[13] As a preferred feature of the present invention, the bearing member may include a circular internal wheel, which is configured such that the steering shaft is integrally coupled to the inner side thereof, an external wheel, which is configured such that the inner side thereof is in contact with and supports a portion of the outer side of the internal wheel so that the internal wheel slides therein, and an outer bearing, which is configured to support the external wheel and is coupled with one end of the horizontal frame.

[14] As another preferred feature of the present invention, it is preferred that the outer bearing be configured such that the inner side thereof is in contact with and supports a portion of the outer side of the external wheel so that the external wheel slides therein, that an external wheel fastening hole be formed in an exposed portion of the external wheel, which is not in contact with the outer bearing, in the longitudinal direction of the horizontal frame, that one or more internal wheel fastening holes, which are arranged in the axial direction of the steering shaft so as to correspond to the external wheel fastening hole, be formed in the internal wheel, and that the bearing member further include a fastening pin, which is removably inserted into both the internal wheel fastening hole and the external wheel fastening hole, each of which is selected by a user to change and fix an angle between the steering shaft and the horizontal frame.

[15] Furthermore, an external wheel fastening hole may be formed in an exposed portion of the external wheel, which is not in contact with the outer bearing, in the longitudinal direction of the horizontal frame, and the internal wheel may include a fastening protrusion, which protrudes opposite the external wheel fastening hole to be inserted into the external wheel fastening hole and be coupled thereto.

[16] Furthermore, the steering shaft may include an engaging protrusion, which is caught in the upper end of the external wheel to thus restrict the sliding range of the internal wheel when the steering shaft is inclined along with the internal wheel in the multiple directions.

[17] In addition, it is preferred that the front wheel steering device further include an elastic member, which is interposed between the external wheel and the engaging protrusion, and provides elastic restoring force between the external wheel and the engaging protrusion when the steering shaft is inclined in the multiple directions.

[18] Furthermore, it is preferred that the bearing member further include a leaf spring, which is interposed between the external wheel and the outer bearing, and provides elastic restoring force when the steering shaft is rotated.

[19] As another preferred feature of the present invention, the external wheel and the engaging protrusion are made of respective magnets, the magnetic poles of which are arranged such that repulsive force acts therebetween.

[20] The characteristics and advantages of the present invention will become more apparent from the following detailed description in conjunction with the accompanying drawings. Prior to reading the detailed description of the present invention, it must be understood that the terms or words used in the specification and claims of the present invention should not necessarily be understood according to their general meanings or dictionary definitions, but should be understood to have meanings and to represent concepts conforming to the technical spirit of the present invention on the basis of the principle by which inventors can define the concept of terms properly to explain their invention in the best way.

Advantageous Effects

[21] As described above, the front wheel steering device of the present invention has the following advantages.

[22] First, a single bearing member, which is formed to have a simple structure, is implemented such that the steering shaft can not only be rotated around the axis defined by the longitudinal direction of the steering shaft, but can also be inclined, thus achieving smooth cornering and comfortable riding when turning is conducted.

[23] Second, it is possible to change and fix the angle between the steering shaft and the horizontal frame, so that the driving of a vehicle, in which the front wheel steering device, which is formed to have a structure suitable for traveling conditions, is provided, can be facilitated.

[24] Third, when the steering shaft is rotated around the axis, which is defined by the longitudinal direction of the steering shaft, or is inclined with respect to the axis defined by the longitudinal direction of the horizontal frame, the steering shaft can be restored to its original position using elasticity, thus increasing convenience for drivers and drivers' safety. Brief Description of the Drawings

[25] FIG. 1 is a perspective view showing a front wheel steering device according to a first embodiment of the present invention;

[26] FIG. 2 is a sectional view taken along line II-II of FIG. 1 ;

[27] FIG. 3 is a section view taken along line Hi-Ill of FIG. 2;

[28] FIG. 4 is a side sectional view showing principal parts of a front wheel steering device according to a second embodiment of the present invention;

[29] FIG. 5 is a partially enlarged view of portion A of FIG. 4;

[30] FIG. 6 is a side sectional view showing the state in which a fastening pin is coupled such that the angle between the steering shaft and the horizontal frame of the front wheel steering device, shown in FIG. 4, is changed;

[31] FIG. 7 is a side sectional view showing principal parts of a front wheel steering dev ice according to a third embodiment of the present invention;

[32] FIG. 8 is a partially enlarged view of portion B of FIG. 7;

[33] FIG. 9 is a side sectional view showing principal parts of a front wheel steering device according to a fourth embodiment of the present invention; and [34] FIG. 10 is a side sectional view showing principal parts of a front wheel steering device according to a fifth embodiment of the present invention.

[35] <Description of reference numerals of principal elements>

[36] 10, 20, 30, 40: front wheel steering device

[37] 100: handle 110, 410: steering shafts

[38] 120, 220, 320, 420: bearing members

[39] 121, 221, 321, 421: internal wheel

[40] 123, 223, 323, 423: external wheel

[41] 125 , 225 , 425 : outer bearings

[42] 130: horizontal frame

[43] 221a: internal wheel fastening hole

[44] 223a, 323a: external wheel fastening hole

[45] 227: fastening pin 321b: fastening protrusion

[46] 411: engaging protrusion 429: leaf spring

[47] 440: elastic member

Mode for the Invention

[48] The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description.

[49] A front wheel steering device according to a preferred embodiment of the present invention is described in detail with reference to the accompanying drawings below.

[50] First, it should be noted that the same reference numerals are used throughout the different drawings to designate the same or similar components. In the description of the present invention, descriptions of related well-known functions or constructions are omitted so as not to make the gist of the present invention unclear.

[51] FIG. 1 is a perspective view showing a front wheel steering device according to a first embodiment of the present invention, FIG. 2 is a sectional view taken along line π-π of FIG. 1, and FIG. 3 is a section view taken along line Hi-Ill of FIG. 2.

[52] As shown in FIG. 1, the front wheel steering device 10 according to the first embodiment of the present invention includes a handle 100, a steering shaft 110, a bearing member 120 and a horizontal frame 130.

[53] The handle 100 is provided for a driver to conduct steering. The driver conducts steering by manipulating the handle 100. The shape of the above-described handle 100 is not limited only to the shape shown in FIG. 1, and may be modified to be any of various shapes for the purpose of the present invention.

[54] The steering shaft 110 is configured such that one end thereof is coupled to the lower end of the central portion of the handle 100 and extends downwards from the lower end. The shape of the above-described steering shaft 110 is also not limited only to the shape shown in FIG. 1, and may be modified to be any of various shapes for the purpose of the present invention.

[55] The bearing member 120 is configured such that the steering shaft 110 is coupled to the inner side of the bearing member 120. The bearing member 120 supports the steering shaft 110 so that the steering shaft 110 can be rotated around an axis or can be inclined in multiple directions.

[56] The horizontal frame 130 is configured such that one end thereof is coupled to the bearing member 120 to form a predetermined angle with the steering shaft 110.

[57] Here, the bearing member 120, as shown in FIGS. 2 and 3, includes a circular internal wheel 121, which is configured such that the steering shaft 110 is integrally coupled to the inner side thereof, an external wheel 123, which is configured such that the inner side thereof is in contact with and supports a portion of the outer side of the internal wheel 121 so that the internal wheel 121 can slide therein, and an outer bearing 125, which is configured to support the external wheel 123 and is coupled with one end of the horizontal frame 130.

[58] The internal wheel 121 has a circular shape, and the inner side of the external wheel

123 is in contact with and supports a portion of the outer side of the internal wheel 121 so that the internal wheel 121 can slide therein, and thus the circular internal wheel 121 can be rotated in multiple directions from the inner side of the external wheel 123. The steering shaft 110 is integrally coupled with the internal wheel 121, so that the steering shaft 110, along with the internal wheel 121, can be rotated around the axis or can be inclined in the multiple directions.

[59] Accordingly, the driver can not only rotate the steering shaft 110 around the axis by manipulating the handle, but also can incline the steering shaft 110 in multiple directions, and thus smooth cornering and comfortable riding can be achieved when turning is conducted.

[60] That is, the circular internal wheel 121 is integrally coupled with the steering shaft

110 and is configured to slide in the external wheel 123, so that the steering shaft 110 can be rotated around the axis in the direction in which the internal wheel 121 slides, or can be inclined in the multiple directions.

[61] Furthermore, the outer bearing 125 supports a portion of the outer side of the external wheel 123. Accordingly, it is preferred that a portion of the outer side of the external wheel 123 be inserted into the cylindrical hole of the outer bearing 125 and be in contact with and supported by the outer bearing 125, and that the external wheel 123 be fastened and supported so as not to slide.

[62] The reason for this is because, when the steering shaft 110 rotates around the axis, the internal wheel 121, which is integrally coupled with the steering shaft 110, slides in the external wheel 123, so that it is not necessary for the external wheel 123 to slide in the outer bearing 125, and, in addition, it is preferred that, in order to achieve stable steering in response to the manipulation of the handle 100, only the internal wheel 121, which is integrally coupled with the steering shaft 110, be formed to rotate around the axis and to be inclined in multiple directions, and that the external wheel 123 be fastened to the outer bearing 125.

[63] As described above, the steering shaft 110 can be rotated around the axis and can be inclined in multiple directions, so that, when the driver manipulates the handle 100, various steering effects can be achieved using the bearing member 120 as the center of rotation, and, in particular, smooth cornering can be achieved when turning is conducted.

[64] A front wheel steering device according to a second embodiment of the present invention is described with reference to FIGS. 4 to 6 below.

[65] FIG. 4 is a side sectional view showing principal parts of the front wheel steering device according to the second embodiment of the present invention, FIG. 5 is a partially enlarged view of portion A of FIG. 4, and FIG. 6 is a side sectional view showing the state in which a fastening pin is coupled such that the angle between the steering shaft and the horizontal frame of the front wheel steering device, shown in FIG. 4, is changed.

[66] Referring to FIGS. 1 and 4, the front wheel steering device 20 according to the second embodiment of the present invention includes a handle 100, a steering shaft 110, a bearing member 220, and a horizontal frame 130.

[67] Referring to FIGS. 4 and 5, the outer bearing 225 is configured such that the inner side thereof is in contact with and supports a portion of the outer side of the external wheel 223 so that the external wheel 223 can slide therein. An external wheel fastening hole 223 a is formed in the exposed portion of the external wheel 223, which is not in contact with the outer bearing 225, in the longitudinal direction of the horizontal frame 130. One or more internal wheel fastening holes 221a, which are arranged in the axial direction of the steering shaft 110 so as to correspond to the external wheel fastening hole 223 a, are formed in the internal wheel 221. The bearing member 220 further includes a fastening pin 227, which is removably inserted into both the internal wheel fastening hole 221a and the external wheel fastening hole 223a, which are selected by a user to change and fix the angle between the steering shaft 110 and the horizontal frame 130.

[68] The fastening pin 227 is inserted into both the external wheel fastening hole 223a and the internal wheel fastening hole 221a to pass therethrough, thus fixing the angle between the steering shaft 110 and the horizontal frame 130.

[69] In the front wheel steering device 20 according to the second embodiment of the present invention, the outer bearing 225 supports a portion of the outer side of the external wheel 223 so that the external wheel 223 can slide therein, and the external wheel 223 and the internal wheel 221 are connected to each other by the fastening pin 227, and thus the internal wheel 221 cannot cause the steering shaft 110 to rotate around the axis while sliding in the external wheel 223. For this reason, the internal wheel 221 and the external wheel 223 must be integrally provided such that the steering shaft 110 can be rotated around the axis.

[70] That is, the external wheel 223 is coupled to the internal wheel 221 by the fastening pin 227, and the outer bearing 225 is configured such that the inner side thereof is in contact with and supports a portion of the outer side of the external wheel 223 so that the external wheel 223 can slide therein, and thus the external wheel 223, along with the internal wheel 221, can cause the steering shaft 110 to rotate around the axis.

[71] In the case where the external wheel fastening hole 223a is formed in the surface of the external wheel 223, which is in contact with the outer bearing 225, a problem occurs in that the fastening pin 227, which is inserted from the outside, cannot be separated. Accordingly, it is preferred that the external wheel fastening hole 223a be formed in the surface of the external wheel 223, which is not in contact with the outer bearing 225, so that the fastening pin 227 can prevent the external wheel 223 from restricting the rotation of the steering shaft 110 and can be freely separated.

[72] Furthermore, as shown in FIG. 6, the fastening pin 227 is inserted both into any of the one or more internal wheel fastening holes 221a, which are arranged in the axial direction of the steering shaft 110, and into the external wheel fastening hole 223a, and thus the angle between the steering shaft 110 and the horizontal frame 130 can be fixed at a desired angle.

[73] The driver can stably drive a vehicle while taking a desired posture by fixing the angle between the steering shaft 110 and the horizontal frame 130, and can change the structure of the device so that the device is suitable for long distance traveling or short distance traveling by changing the angle between the steering shaft 110 and the horizontal frame 130.

[74] Accordingly, the present invention enables the user to merely insert the fastening pin

227 into any of the plurality of internal wheel fastening holes 221a and the external wheel fastening hole 223a to achieve a connection suitable for the purpose of traveling, and is thus convenient, as described above.

[75] Since the handle, the steering shaft and the horizontal frame of the front wheel steering device 20 according to the second embodiment of the present invention are the same as the handle 100, the steering shaft 110 and the horizontal frame 130 of the front wheel steering device 10 according to the first embodiment of the present invention, the same reference numerals as those of the first embodiment are used, and in addition, repeated descriptions are omitted. [76] A front wheel steering device according to a third embodiment of the present invention is described with reference to FIGS. 7 and 8 below.

[77] FIG. 7 is a side sectional view showing principal parts of the front wheel steering device according to the third embodiment of the present invention, and FIG. 8 is a partially enlarged view of portion B of FIG. 7.

[78] Referring to FIGS. 1 and 7, the front wheel steering device 30 according to the third embodiment of the present invention includes a handle 100, a steering shaft 110, a bearing member 320, and a horizontal frame 130.

[79] As shown in FIGS. 7 and 8, in the front wheel steering device 30 according to the third embodiment of the present invention, an external wheel fastening hole 323a is formed in the exposed portion of the external wheel 323, which is not in contact with the outer bearing 225, in the longitudinal direction of the horizontal frame 130. The internal wheel 321 includes a fastening protrusion 321b, which protrudes opposite the external wheel fastening hole 323a to be inserted into the external wheel fastening hole 323a and be coupled thereto.

[80] The fastening protrusion 321b has a function similar to that of the fastening pin 227 of the front wheel steering device 20 according to the second embodiment of the present invention.

[81] That is, the fastening protrusion 321b is inserted into the external wheel fastening hole 323a, and thus the external wheel 323 and the internal wheel 321 are coupled to each other and the angle between the steering shaft 310 and the horizontal frame 330 is fixed.

[82] Here, the protrusion 321b is not separated, as in the fastening pin 227, and thus the angle between the steering shaft 110 and the horizontal frame 130 cannot be not changed.

[83] Since the handle 100, the steering shaft 110, the outer bearing 225 and the horizontal frame 130 of the front wheel steering device 30 according to the third embodiment of the present invention are the same as the handle 100, the steering shaft 110, the outer bearing 225 and the horizontal frame 130 of the front wheel steering device 20 according to the second embodiment of the present invention, repeated descriptions are omitted.

[84] A front wheel steering device according to a fourth embodiment of the present invention is described with reference to FIG. 9 below.

[85] FIG. 9 is a side sectional view showing principal parts of the front wheel steering device according to the fourth embodiment of the present invention.

[86] Referring to FIGS. 1 and 9, the front wheel steering device 40 according to the fourth embodiment of the present invention includes a handle 100, a steering shaft 410, a bearing member 420, a horizontal frame 130, and an elastic member 440. [87] The steering shaft 410 includes an engaging protrusion 411, which is caught in the upper end of the external wheel 423 to thus restrict the sliding range of the internal wheel 421 when the steering shaft 410 is inclined along with the internal wheel 421 in the multiple directions.

[88] When the engaging protrusion 411 is provided and when the steering shaft 410 is inclined along with the internal wheel 421, the engaging protrusion 411 is caught in the upper end of the external wheel 423, and thus the sliding range of the internal wheel 421 is restricted, so that the inclination is attained within a limited range.

[89] Accordingly, the case in which a vehicle loses balance and is overturned due to excessive inclination can be prevented.

[90] Furthermore, the elastic member 440 is interposed between the external wheel 423 and the engaging protrusion 411, and provides restoring force, caused by elasticity, between the external wheel 423 and the engaging protrusion 411 when the steering shaft 410 is inclined in the multiple directions.

[91] As shown in FIG. 9, the elastic member 440 is located between the upper end of the external wheel 423 and the engaging protrusion 411, and restores the steering shaft 410 to its original location in such a way that it is compressed and is then expanded by elasticity when the steering shaft 410 is inclined.

[92] Accordingly, the elastic member 440 functions to help the inclined steering shaft 410 be perpendicular to the ground, and thus an effect of decreasing the amount of force that the driver is required to exert in order to maintain a straight trajectory can be achieved.

[93] A rubber material or a compression spring may be used as the elastic member 440, but the present invention is not limited thereto. Any kind of material that has an elastic restoring force may be used to achieve the purpose of the present invention.

[94] Furthermore, the bearing member 420 further includes a leaf spring 429, which is configured to connect the outer surface of the external wheel 423 and the inner surface of the outer bearing 425 with each other and is restored by elasticity when the external wheel 423 is integrally coupled with the internal wheel 421 and when the steering shaft 410 is rotated around the axis.

[95] The leaf spring 429 is interposed between the external wheel 423 and the outer bearing 425. Accordingly, the leaf spring 429 does not operate in a manner dependent on the inclination of the steering shaft 410, and applies restoring force only when the internal wheel 421 and the external wheel 423 are connected by the fastening pin 227 and when the steering shaft 410 is rotated around the axis.

[96] That is, when the internal wheel 421 and the external wheel 423, which are coupled by the fastening pin 227, slide in the outer bearing 425 and thus the leaf spring 429 is bent, restoration to the original position is achieved by the elasticity of the leaf spring 429.

[97] Here, the member that is interposed between the external wheel 423 and the outer bearing 425 to provide elastic restoration force is not limited to the leaf spring 429, and any kind of material that has an elastic restoring force may be used to achieve the purpose of the present invention.

[98] Since the handle 100, the horizontal frame 130 and the fastening pin 227 of the front wheel steering device 40 according to the fourth embodiment of the present invention are the same as the handle 100, the horizontal frame 130 and the fastening pin 227 of the front wheel steering device 20 according to the second embodiment of the present invention, repeated descriptions are omitted.

[99] A front wheel steering device according to a fifth embodiment of the present invention is described with reference to FIG. 10 below.

[100] FIG. 10 is a side sectional view showing principal parts of the front wheel steering device according to the fifth embodiment of the present invention. The front wheel steering device 40 according to the fifth embodiment of the present invention is similar to the front wheel steering device according to the fourth embodiment of the present invention, described above, and is technically characterized in that the engaging protrusion 411 and the external wheel 423 in the fourth embodiment are replaced with respective magnets, having magnetic poles such that they are mutually repulsed by repulsive force.

[101] That is, the steering shaft 410 includes an engaging protrusion 41 Im, which is made of a magnet, which is caught in the upper end of the external wheel 423 to thus restrict the sliding range of the internal wheel 421 when the steering shaft 410 is inclined along with the internal wheel 421 in the multiple directions. In this case, the magnetic poles of the engaging protrusion 41 Im are arranged such that repulsive force acts therebetween in the direction leading away from an external wheel 423m, which is made of a magnet and which will be described later.

[102] When the steering shaft 410 is inclined along with the internal wheel 421 due to the above-described construction, repulsive force acts between the external wheel 423m and the engaging protrusion 411m, and thus the sliding range of the internal wheel 421 is restricted. As a result, the inclination is achieved within a limited range.

[103] Accordingly, the case in which a vehicle loses its balance and is turned over due to excessive inclination can be prevented.

[104] Meanwhile, since the handle 100, the horizontal frame 130 and the fastening pin 227 of the front wheel steering device 40 according to the fifth embodiment of the present invention are the same as the handle 100, the horizontal frame 130 and the fastening pin 227 of front wheel steering device 20 according to the second embodiment of the present invention, repeated descriptions are omitted. [105] Although the invention has been described above based on the defined embodiments and the drawings, the present invention is not limited thereto, and may be modified and changed in various ways based on the technical spirit of the present invention and within the range defined by the following claims by a person having ordinary knowledge in the technical field to which the present invention pertains.

[106]

Claims

[1] A front wheel steering device, comprising: a handle manipulated by a driver; a steering shaft configured such that one end thereof is coupled to a lower end of a central portion of the handle and extends downwards from the lower end; a bearing member configured such that the steering shaft is coupled to an inner side of the bearing member, the bearing member supporting the steering shaft so that the steering shaft 110 is rotated around an axis or is inclined in multiple directions; and a horizontal frame configured such that one end thereof is coupled to the bearing member to form a predetermined angle with the steering shaft.

[2] The front wheel steering device according to claim 1, wherein the bearing member comprises: a circular internal wheel, which is configured such that the steering shaft is integrally coupled to an inner side thereof; an external wheel, which is configured such that an inner side thereof is in contact with and supports a portion of an outer side of the internal wheel so that the internal wheel slides therein; and an outer bearing, which is configured to support the external wheel and is coupled with one end of the horizontal frame.

[3] The front wheel steering device according to claim 2, wherein: the outer bearing is configured such that an inner side thereof is in contact with and supports a portion of an outer side of the external wheel so that the external wheel slides therein; an external wheel fastening hole is formed in an exposed portion of the external wheel, which is not in contact with the outer bearing, in a longitudinal direction of the horizontal frame; one or more internal wheel fastening holes, which are arranged in an axial direction of the steering shaft so as to correspond to the external wheel fastening hole, are formed in the internal wheel; and the bearing member further comprises a fastening pin, which is removably inserted into both the internal wheel fastening hole and the external wheel fastening hole, each of which is selected by a user to change and fix an angle between the steering shaft and the horizontal frame.

[4] The front wheel steering device according to claim 2, wherein: an external wheel fastening hole is formed in an exposed portion of the external wheel, which is not in contact with the outer bearing, in a longitudinal direction of the horizontal frame; and the internal wheel comprises a fastening protrusion, which protrudes opposite the external wheel fastening hole to be inserted into the external wheel fastening hole and be coupled thereto.

[5] The front wheel steering device according to any one of claims 2 to 4, wherein the steering shaft comprises an engaging protrusion, which is caught in an upper end of the external wheel to thus restrict a sliding range of the internal wheel when the steering shaft is inclined along with the internal wheel in the multiple directions.

[6] The front wheel steering device according to claim 5, further comprising an elastic member, which is interposed between the external wheel and the engaging protrusion, and provides elastic restoring force between the external wheel and the engaging protrusion when the steering shaft is inclined in the multiple directions.

[7] The front wheel steering device according to claim 6, wherein the bearing member further comprises a leaf spring, which is interposed between the external wheel and the outer bearing, and provides elastic restoring force when the steering shaft is rotated.

[8] The front wheel steering device according to claim 5, wherein the external wheel and the engaging protrusion are made of respective magnets, magnetic poles of which are arranged such that repulsive force acts therebetween.