WO2006107152A1

WO2006107152A1 - Speed change hub for bicycle

Info

Publication number: WO2006107152A1
Application number: PCT/KR2006/000937
Authority: WO
Inventors: Doo-Young Lee
Original assignee: Zast Co., Ltd; Nakano Iron Works Co, Ltd.
Priority date: 2005-03-15
Filing date: 2006-03-15
Publication date: 2006-10-12
Also published as: JP4982479B2; KR100915378B1; WO2006107152A8; JP2008533404A; KR20070119029A

Abstract

The present invention provides a speed change hub for bicycles which is easily manipulated, prevents noise and vibration from occurring when changing speed, and has a simple structure. The speed change hub includes: a hub shaft (100), which is provided between frames; a power transmission unit, which has a driven sprocket (310) and a driver (320); a multistage speed change unit, having a carrier (490), a plurality of multistage planetary gears (420), sun gears (430) and (440), and a ring gear (410); a speed change output unit, having a hub shell (600) and clutch means (640) and (650); an input/output control unit, having clutch means (510) and (650) and an input/output control plate (520); and a speed change control unit, having a movable pin (220) and (230), a restoring spring (210), and control members (240), (250) and (260).

Description

Description SPEED CHANGE HUB FOR BICYCLE

Technical Field

[1] The present invention relates, in general, to speed change hubs and, more particularly, to a built-in type speed change device for bicycles which is used in a power transmission comprising a chain or belt, is installed in a hub, changes speed by changing gear ratios, and is manipulated by an outside lever. Background Art

[2] Generally, in speed change devices for bicycles, a plurality of sprockets, having different diameters, is provided at each of relative front and rear positions on a bicycle, and gear shifting is conducted by moving a chain between the sprockets. Such a speed change device, in which a plurality of sprockets having different diameters is provided at each of relative front and rear positions of a bicycle and speed is changed by moving a chain between the sprockets, is called an open type speed change device. In addition, there is a built-in type speed change device, in which speed is changed using gear trains installed in a hub.

[3] However, in the speed change device using the several sprockets having different diameters, when changing speed, noise and impact occur. Furthermore, because it is exposed outside, there is a possibility of safety hazards, for example, clothes of a user can become trapped between the sprockets.

[4] Meanwhile, to solve the above problem, the built-in type speed change device, which is installed in a hub of a rear wheel of a bicycle, was proposed. In this device, gear trains are disposed in a hub shell, so that speed is changed depending on the ratio of the number of gear teeth. However, this device has a disadvantage in that the structure thereof is complex. Disclosure of Invention Technical Problem

[5] 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 speed change hub for bicycles in which speed is changed by a rider manipulating a lever, and noise and vibration are prevented from occurring when changing speed, and which has no chain and thus can be covered with a cover, thus preventing clothes of the rider from becoming trapped in the device, and in which, because of the increased number of speeds, the rider can more conveniently change speed appropriate to the conditions, for example, when traveling on a slope or over a long distance.

Advantageous Effects [6] As described above, the speed change hub for a bicycle according to the present invention allows a rider to easily manipulate it, prevents noise and vibration from occurring when changing speed, and has a simple structure, and, because of the increased number of speeds, the rider can more conveniently change speed appropriate to the conditions, for example, when traveling on a slope or over a long distance.

[7] Furthermore, the speed change hub according to the present invention has no chain.

Therefore, because it can be covered with a cover, the clothes of the rider are prevented from becoming trapped in the device. Thus, the rider can use the bicycle more safely and conveniently.

[8] Although the preferred embodiments of the present invention have 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. Brief Description of the Drawings

[9] FIG. 1 is a sectional view of a speed change hub, according to an embodiment of the present invention;

[10] FIG. 2 is views illustrating the operation of a speed change control unit of the speed change hub according to the present invention;

[11] FIG. 3 is an exploded perspective view showing the speed change control unit of the speed change hub according to the present invention;

[12] FIG. 4 is views illustrating the operation of an input/output control unit of the speed change hub according to the present invention;

[13] FIG. 5 is views showing another embodiment of the input/output control unit of the speed change hub according to the present invention;

[14] FIG. 6 is a sectional view of a speed change hub, according to a further embodiment of the present invention;

[15] FIG. 7 is a partially broken perspective view showing a speed change control unit of the speed change hub of FIG. 6;

[16] FIG. 8 is a perspective view showing a control member of the speed change hub of

FIG. 6;

[17] FIG. 9 is a front view showing a first sun gear of the speed change hub of FIG. 6; and

[18] FIG. 10 is a front view showing a second sun gear of the speed change hub of FIG.

6. Best Mode for Carrying Out the Invention

[19] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. [20] FIG. 1 is a sectional view of a speed change hub for bicycles, according to the present invention.

[21] In order to accomplish the above object, the present invention provides a speed change hub for bicycles which is used in a power transmission device, particularly, using a chain or belt, and which is a built-in type speed change device that is installed in a hub, changes speed by changing a gear ratio, and is manipulated by an outside lever. The speed change hub of the present invention includes a hub shaft 100, which is provided between frames and is provided with a ratchet 110, having a spline shape, on a circumferential outer surface thereof.

[22] The speed change hub further includes a power transmission unit. The power transmission unit has a driven sprocket 310, which receives clockwise drive force from a drive sprocket (not shown), and a driver 320, which is coupled at a first end thereof to the driven sprocket 310 and has a ratchet 321 on a second end thereof. A clutch means 330 is provided on the circumferential inner surface of the driver 320.

[23] The speed change hub further includes a multistage speed change unit. The multistage speed change unit has a carrier 490, which receives drive force from the power transmission unit. A ratchet 491 is provided on a first end of the carrier 490, and a plurality of multistage planetary gears 420 and a third clutch means 640 are provided on a second end of the carrier 490. The multistage speed change unit further has two or more sun gears 430 and 440, which engage with the multistage planetary gears 420. The sun gears 430 and 440 have forward and reverse clutch means 431, 432, 441 and 442 on circumferential inner surfaces thereof. The multistage speed change unit further has a ring gear 410, which engages with the multistage planetary gears 420 and has second and fourth clutch means 510 and 650 on respective circumferential inner and outer surfaces of a second end thereof.

[24] The speed change hub further includes a speed change output unit. The speed change output unit has a hub shell 600, which receives drive force from the carrier 490 and the ring gear 410, and the third and fourth clutch means 640 and 650, which are disposed at respective predetermined positions between the carrier 490 and the hub shell 600 and between the ring gear 410 and the hub shell 600. Only a preceding one of the third and fourth clutch means is selectively operated.

[25] The speed change hub further includes an input/output control unit. The input/ output control unit has the second and fourth clutch means 510 and 650, which are provided between the ring gear 410 and the driver 320, and an input/output control plate 520, which is controlled by combination of the second and fourth clutch means 510 and 650 and has a protrusion at a predetermined position thereof.

[26] The speed change hub further includes a speed change control unit. The speed change control unit has a plurality of movable pins 220 and 230, which are moved by an outside lever, a restoring spring 210, which returns the movable pins 220 and 230 to their initial positions, and control members 240, 250 and 260, which are manipulated by the movable pin 220 and 230 and control both the first clutch means 330 provided on the driver 320 and clutch means 450, 460, 470 and 480 mounted to the sun gears.

[27] FIG. 2 is views illustrating the operation of the speed change control unit of the speed change hub of the present invention. FIG. 3 is an exploded perspective view showing the speed change control unit of the speed change hub of the present invention. The movable pins 220 and 230, which are provided in the hub shaft 100, are moved to the left or right by the operation of the outside lever (not shown) or by the operation of the restoring spring 210, thus moving the control member 240, which is fitted over the hub shaft 100 so as to be movable to the left and right. Due to the movement of the control member 240, the forward and backward control pins 250 and 260, having protrusions and notches, control the clutch means 450, 460, 470 and 480, which are mounted to the circumferential inner surfaces of the first and second sun gears 430 and 440, thus making it possible to change the speed of the bicycle. Furthermore, the movement of the control member 240 results in the release or engagement of the first clutch means 330, which is mounted to the driver 320.

[28] FIG. 4 is views illustrating the operation of the input/output control unit of the speed change hub of the present invention. In low speed first gear or low speed second gear, the second clutch means 510, which receives power from the driver 320, is rotated at a predetermined angle to rotate the input/output control plate 520. At this time, the fourth clutch means 650 is released from a ratchet 601 of the hub shell 600 by the rotation of the input/output control plate 520. Furthermore, in middle speed gear, high speed first gear or high speed second gear, because the hub shell 600 rotates faster than the fourth clutch means 650, the hub shell 600 and the fourth clutch means 650 slide with respect to each other without engaging with each other.

[29] FIG. 5 is views showing another embodiment of the input/output control unit of the speed change hub of the present invention. In this case, in low speed first gear or low speed second gear, the input/output control plate 520, which has protrusions on inner and outer surfaces thereof, is rotated at a predetermined angle by power transmitted from the ratchet 321 of the driver 320. Thereby, the fourth clutch means 65 is released from the ratchet 601 of the hub shell 600 and, simultaneously, the second clutch means 510 engages with the ratchet 321 of the driver 320. Furthermore, in middle speed gear, high speed first gear or high speed second gear, because the ring gear 410 rotates faster than the driver 320, the input/output control plate 520 slides with respect to the driver 320 without engaging with the driver 320.

[30] FIG. 1 is a sectional view showing the speed change hub for vehicles according to the present invention. The operation and effect of the present invention will be described herein below with reference to FIG. 1. In the present invention, when a user moves the speed change unit of the speed change hub by manipulating the lever (not shown), the bicycle is shifted to low speed first gear, low speed second gear, middle speed gear, high speed first gear, or high speed second gear.

[31] 1. when in low speed first gear

[32] When in low speed first gear, the first clutch means 330, which is mounted to the driver 320, is in a released state, and the first reverse clutch means 460, which is mounted to the circumferential inner surface of the first sun gear 430, is also in a released state. In this state, drive force of the drive sprocket is transmitted to the driven sprocket 310, which is connected to the drive sprocket through the chain. The clockwise rotation of the driven sprocket 310 is transmitted to the driver 320, which is held at one end thereof. The operation of the driver 320 is transmitted to the second clutch means 510, so that the second clutch means 510 is rotated at a predetermined angle and thus rotates the input/output control plate 520. Then, the fourth clutch means 650 is released from the ratchet 620, which is provided on the circumferential inner surface of the hub shell 600, and the drive force is transmitted from the second clutch means 510 to the ring gear 410. Then, the multistage planetary gears 420, which engage with the ring gear 410, are operated by the rotation of the ring gear 410. Due to the operation of the multistage planetary gears 420, the second sun gear 440, which engages with the multistage planetary gears 420, has a tendency to rotate, but the second sun gear 440 is stopped by the second reverse clutch means 480, thereby the carrier 490 is operated. At this time, the first sun gear 430 is in a state of having been released from the first reverse clutch means 460. The drive force, which has been transmitted to the carrier 490, is transmitted to the hub shell 600 through the ratchet 610, which is provided on the circumferential inner surface of the hub shell 600. Therefore, a wheel, which is coupled to the hub shell 600 by spokes, is rotated due to the rotation of the hub shell 600, thus moving the bicycle.

[33] 2. when in low speed second gear

[34] When in low speed second gear, the first clutch means 330, which is mounted to the driver 320, is in a released state, and the second reverse clutch means 470, which is mounted to the circumferential inner surface of the second sun gear 440, is also in a released state. In this state, drive force of the drive sprocket is transmitted to the driven sprocket 310, which is connected to the drive sprocket through the chain. The clockwise rotation of the driven sprocket 310 is transmitted to the driver 320, which is held at one end thereof. The operation of the driver 320 is transmitted to the second clutch means 510, so that the second clutch means 510 is rotated at a predetermined angle and thus rotates the input/output control plate 520. Then, the fourth clutch means 650 is released from the ratchet 610, which is provided on the circumferential inner surface of the hub shell 600, and the drive force is transmitted from the second clutch means 510 to the ring gear 410. Then, the multistage planetary gears 420, which engage with the ring gear 410, are operated by the rotation of the ring gear 410. Due to the operation of the multistage planetary gears 420, the first sun gear 430, which engages with the multistage planetary gears 420, has a tendency to rotate, but the first sun gear 430 is stopped by the first reverse clutch means 460, thereby the carrier 490 is operated. At this time, the second sun gear 440 is in a state of having been released from the second reverse clutch means 480. The drive force, which has been transmitted to the carrier 490, is transmitted to the hub shell 600 through the ratchet 610, which is provided on the circumferential inner surface of the hub shell 600. Therefore, the wheel, which is coupled to the hub shell 600 by the spokes, is rotated due to the rotation of the hub shell 600, thus moving the bicycle.

[35] 3. when in middle speed gear

[36] When in middle speed gear, the first forward and reverse clutch means 450 and 460, which are mounted to the circumferential inner surface of the first sun gear 430, and the second forward and reverse clutch means 470 and 480, which are mounted to the circumferential inner surface of the second sun gear 440, are in released states. In this state, drive force of the drive sprocket is transmitted to the driven sprocket 310, which is connected to the drive sprocket through the chain. The clockwise rotation of the driven sprocket 310 is transmitted to the driver 320, which is held at one end thereof. The operation of the driver 320 is transmitted to the carrier 490 and the ring gear 410. The drive force, which is transmitted to the carrier 490 and the ring gear 410, rotates the carrier 490, the multistage planetary gears 420 and the first and second sun gears 430 and 440, which are in an integrated state. Then, the hub shell 600 is rotated by the drive force because the third clutch means 640, which is mounted to the carrier 490, engages with the ratchet 610, which is provided on the circumferential inner surface of the hub shell 600. Therefore, the wheel, which is coupled to the hub shell 600 by the spokes, is rotated due to the rotation of the hub shell 600, thus moving the bicycle.

[37] 4. when in high speed first gear

[38] When in low speed second gear, the first forward clutch means 450, which is mounted to the circumferential inner surface of the first sun gear 430, is in a released state. In this state, drive force of the drive sprocket is transmitted to the driven sprocket 310, which is connected to the drive sprocket through the chain. The clockwise rotation of the driven sprocket 310 is transmitted to the driver 320, which is held at one end thereof. The operation of the driver 320 is transmitted to the carrier 490 through the first clutch means 330. The drive force, which is transmitted to the carrier 490, revolves the multistage planetary gears 420 on their own axes and around the axis of the speed change hub. At this time, the second sun gear 440 has a tendency to rotate in a clockwise direction, but is stopped by the second forward clutch means 470. Then, the ring gear 410 is rotated at high speed by rotation of the multistage planetary gears 420 and the carrier 490. Here, the ring gear 410 rotates faster than the carrier 490. Therefore, high speed rotating force, which is transmitted to the ring gear 410, rotates the hub shell 600 through the fourth clutch means 650, which is mounted to the ring gear 410. At this time, the third clutch means 640 slips due to the difference in speed between the hub shell 600 and the carrier 490.

[39] 5. when in high speed second gear

[40] When in low speed second gear, the second forward clutch means 470, which is mounted to the circumferential inner surface of the second sun gear 440, is in a released state. In this state, drive force of the drive sprocket is transmitted to the driven sprocket 310, which is connected to the drive sprocket through the chain. The clockwise rotation of the driven sprocket 310 is transmitted to the driver 320, which is held at one end thereof. The operation of the driver 320 is transmitted to the carrier 490 through the first clutch means 330. The drive force, which is transmitted to the carrier 490, revolves the multistage planetary gears 420 on their own axes and around the axis of the speed change hub. At this time, the first sun gear 430 has a tendency to rotate in a clockwise direction, but it is stopped by the first forward clutch means 450. Then, the ring gear 410 is rotated at high speed by rotation of the multistage planetary gears 420 and the carrier 490. Here, the ring gear 410 rotates faster than the carrier 490. Therefore, high speed rotating force, which is transmitted to the ring gear 410, rotates the hub shell 600 through the fourth clutch means 650, which is mounted to the ring gear 410. At this time, the third clutch means 640 slips due to the difference in speed between the hub shell 600 and the carrier 490.

[41] In the present invention, the speed ratio of the speed change hub of the bicycle between low speed first gear, low speed second gear, high speed first gear and high speed second gear is determined depending on the ratio of the number of teeth between the multistage planetary gears 420, the first sun gear 430, the second sun gear 440 and the ring gear 410.

[42] Hereinafter, a further embodiment of the present invention will be described in detail with reference to the attached drawings.

[43] FIG. 6 is a sectional view of a speed change hub, according to the further embodiment of the present invention.

[44] The further embodiment of the present invention relates to a speed change hub in which a plurality of gear trains is disposed in a hub shell 1600 and is controlled by an outside lever. The speed change hub according to this embodiment comprises a hub shaft 1100, which is provided between frames, is provided with a ratchet 1110 on a circumferential outer surface thereof, and has a hollow structure. [45] The speed change hub further includes a power transmission unit. The power transmission unit has a driven sprocket 1200, which receives drive force from a drive sprocket (not shown) through a chain or belt, and a carrier 1300, which is coupled at a first end thereof to the driven sprocket 1200 and coupled at a second end thereof to a plurality of multistage planetary gears 1420. The carrier 1300 is provided with a third pawl 1310 on a circumferential outer surface thereof.

[46] The speed change hub further includes a multistage speed change unit, which receives drive force from the power transmission unit and conducts a speed change using a ring gear 1410, the multistage planetary gears 1420, and a first sun gear 1430 and a second sun gear 1440.

[47] The speed change hub further includes a speed change control unit. The speed change control unit has control pins 1560 and 1570 and a control member 1510, which controls first and second pawls 1431 and 1441, which are respectively provided on circumferential inner surfaces of the first and second sun gears 1430 and 1440 of the multistage speed change unit. The speed change control unit further has a restoring spring 1520 and a spring guide 1540.

[48] The speed change hub further includes a hub shell 1600, which receives speed change drive force from the power transmission unit by engaging with a fourth pawl 1411 provided on the circumferential outer surface of the ring gear 1410.

[49] FIG. 7 is a partially broken perspective view showing the speed change control unit of the speed change hub according to this embodiment. FIG. 8 is a perspective view showing the control member of the speed change hub according to this embodiment. The control member 1510, which is provided in the hub shaft 1100 and has an obliquely shaped portion on the circumferential outer surface thereof, is moved to the left or right by the manipulation of the outside lever (not shown) or by the operation of the restoring spring 1520. Engagement between the ratchet 1110, which is provided on the circumferential outer surface of the hub shaft 1100, and the first and second pawls 1431 and 1441, which are provided in the first and second sun gears 1430 and 1440, is controlled by extension and contraction of the control pins 1560 and 1570 in response to movement of the control member 1510. Furthermore, the spring guide 1540 makes it possible for the restoring spring 1520 to be smoothly operated.

[50] FIGS. 9 and 10 are front views respectively showing the first sun gear 1430 and the second sun gear 1440. Gear teeth are provided on the circumferential outer surfaces of the gears, and pawl seats are formed in the circumferential inner surfaces of the gears for the first pawl 1431 and the second pawl 1441 to be mounted thereto.

[51] FIG. 6 is a sectional view showing the speed change hub according to this embodiment of the present invention. The operation and effect of the present invention will be described herein below with reference to FIG. 6. [52] In this embodiment of the present invention, the speed change hub can be shifted among three speeds by the manipulating the outside lever, and the speed of the bicycle in each speed is determined depending on the ratio of the number of gear teeth.

[53] When in first speed, the first and second pawls 1431 and 1441, which are provided on the circumferential inner surfaces of the first and second sun gears 1430 and 1440, are in a released state from the ratchet 1110, which is provided on the circumferential outer surface of the hub shaft 1100, due to the operation of the first pawl control pin 1570 and the second pawl control pin 1560 by the movement of the control member 1510. In this state, clockwise drive force of the drive sprocket (not shown) is transmitted to the driven sprocket 1200, which is connected to the drive sprocket through the chain. The carrier 1300, which is held at an end thereof, is operated by rotation of the driven sprocket 1200. The hub shell 1600, which engages with the fourth pawl 1310, is operated by the operation of the carrier 1300. At this time, the hub shell 1600 is rotated through the multistage planetary gears 1420, but because the first sun gear 1430 and the second sun gear 1440 are in the released state from the hub shaft 1100, they does not affect the rotation of the hub shell 1600.

[54] When in second speed, due to the operation of the first pawl control pin 1570 and the second pawl control pin 1560 by the movement of the control member 1510, the first pawl 1431, which is provided on the circumferential inner surface of the first sun gear 1430, engages with the ratchet 1110, which is provided on the circumferential outer surface of the hub shaft 1100, while the second pawl 1440 is in a released state. In this state, clockwise drive force of the drive sprocket (not shown) is transmitted to the driven sprocket 1200. The carrier 1300, which is held at the end thereof, is operated by the rotation of the driven sprocket 1200. Thereby, the multistage planetary gears 1420, which are coupled to the end of the carrier, are rotated. Because the first sun gear engages with the hub shaft 1100, which is supported by the frame, the rotating force of the multistage planetary gears 1420 is transmitted to the ring gear 1410. The rotation of the ring gear 1410 is transmitted to the hub shell 1600 through the fourth pawl 1411, which is provided on the circumferential outer surface of the ring gear 1410. At this time, the third pawl 1310, which is mounted to the carrier 1300, slips due to the difference in the number of revolutions between it and the hub shell 1600.

[55] When in third speed, due to the operation of the first pawl control pin 1570 and the second pawl control pin 1560 by the movement of the control member 1510, the first and second pawls 1431 and 1441, which are provided on the circumferential inner surfaces of the first and second sun gears 1430 and 1440, engage with the ratchet 1110, which is provided on the circumferential outer surface of the hub shaft 1100. In this state, clockwise rotation of the driven sprocket 1200 is transmitted to the carrier 1300. The multistage planetary gears 1420 are rotated by the rotation of the carrier 1300. The rotating force of the multistage planetary gears 1420 is transmitted to the ring gear 1410, because the first sun gear engages with the hub shaft 1100, which is supported by the frame. The rotating force of the ring gear 1410 is transmitted to the hub shell 1600 through the fourth pawl 1411, which is provided on the circumferential outer surface of the ring gear 1410. At this time, the first sun gear 1430 rotates around its own axis while slipping, and the third pawl 1310, which is mounted to the carrier 1300, slips due to the difference in the number of revolutions between it and the hub shell 1600.

Claims

[1] A speed change hub for a bicycle, comprising: a hub shaft provided between frames, with a ratchet, having a spline shape, provided on a circumferential outer surface of the hub shaft; a power transmission unit, comprising: a driven sprocket to receive clockwise drive force from a drive sprocket; and a driver coupled at a first end thereof to the driven sprocket and having a ratchet on a second end thereof, with first clutch means provided on a circumferential inner surface of the driver; a multistage speed change unit, comprising: a carrier to receive the drive force from the power transmission unit, with a ratchet provided on a first end of the carrier, and a plurality of multistage planetary gears and third clutch means provided on a second end of the carrier; the multistage planetary gears; two or more sun gears engaging with the multistage planetary gears, the sun gears having forward and reverse clutch means on circumferential inner surfaces thereof; and a ring gear engaging with the multistage planetary gears, with second and fourth clutch means provided on respective circumferential inner and outer surfaces of a second end of the ring gear; a speed change output unit, comprising: a hub shell to receive the drive force from the carrier and the ring gear; and the third and fourth clutch means disposed at respective predetermined positions between the carrier and the hub shell and between the ring gear and the hub shell, wherein only a preceding one of the third and fourth clutch means is selectively operated; an input/output control unit, comprising: the second and fourth clutch means provided between the ring gear and the driver; and an input/output control plate controlled by combination of the second and fourth clutch means, with a protrusion provided at a predetermined position on the input/output control plate; and a speed change control unit, comprising: a movable pin moved by an outside lever; a restoring spring to return the movable pin to an initial state thereof; and a control member manipulated by the movable pin and controlling both the first clutch means provided on the driver and further clutch means mounted to the sun gears.

[2] The speed change hub for the bicycle according to claim 1, wherein clutch means is provided on the circumferential inner surfaces of the sun gears to prevent clockwise or counterclockwise rotation.

[3] The speed change hub for the bicycle according to claim 1, wherein the speed change control unit is disposed in the hub shaft and comprises: the restoring spring provided in the hub shaft; the movable pin provided so as to be movable to the left and right; the control member provided so as to be movable on the circumferential outer surface of the hub shaft, the control member being coupled to the movable pin, which has a groove and a slide surface on a circumferential outer surface thereof, with an inclined surface formed on a second end of the control member, and a coupling groove formed at a medial position of the control member so that a forward or reverse control pin is coupled to the control member through the coupling groove; the forward or reverse control pin having two or more inclined surfaces.

[4] The speed change hub for the bicycle according to claim 1, wherein the second and fourth clutch means of the input/output control unit are respectively coupled to outer and inner surfaces of the ring gear, and, when the inner clutch means is rotated, the input/output control plate, having the protrusion at the predetermined position, is rotated at a predetermined angle due to grooves formed at regular intervals, thereby the outer clutch means is controlled.

[5] The speed change hub for the bicycle according to claim 1, wherein the second and fourth clutch means of the input/output control unit are respectively coupled to outer and inner surfaces of the ring gear, so that, when the driver is rotated, the input/output control plate, having the protrusions on outer and inner surfaces thereof, engages with the ratchet provided on the driver and is thus rotated at a predetermined angle, and the second and fourth clutch means, which are respectively mounted to inner and outer surfaces of the ring gear, are controlled by the rotation of the input/output control plate.

[6] A speed change hub for bicycles, comprising: a hub shaft provided between frames and having a hollow structure, with a ratchet provided on a circumferential outer surface of the hub shaft; a power transmission unit, comprising: a driven sprocket to receive drive force from a drive sprocket; and a carrier coupled at a first end thereof to the driven sprocket and coupled at a second end thereof to a plurality of multistage planetary gears, with a pawl provided on a circumferential outer surface of the carrier; a multistage speed change unit to receive the drive force from the power transmission unit, the multistage speed change unit comprising: a ring gear having on a circumferential outer surface thereof a pawl seat, on which a pawl is seated; the multistage planetary gears; and first and second sun gears, each having a pawl seat on a circumferential inner surface thereof; a speed change control unit, comprising: a control pin and a control member controlling first and second pawls, which are respectively provided on circum- ferential inner surfaces of the first and second sun gears of the multistage speed change unit, a restoring spring, and a spring guide; and a hub shell to receive the drive force transmitted from the carrier and the ring gear.

[7] The speed change hub for the bicycle according to claim 6, wherein the speed change control unit is installed in the hub shaft and comprises: the control member having oblique shapes formed at regular intervals on a circumferential outer surface thereof; a plurality of control pins operated by the control member; and the restoring spring to move the control member.