Specifically, the present invention relates to a one-way gear assembly that can be applied to a driving shaft or a wheel hub of a bicycle.

The forward and reversed rotational force input through a pedal of the bicycle can be output as a driving force of the wheel in the forward direction. If required, the one-way output can be released so that a power transmission as in the normal bicycle can be realized.

In addition, the present invention relates to a bicycle employing such a one-way gear assembly.

2) Description of Prior Art A variety of one-way gears are well known in the field.

Such one-way gears are all designed using a planetary gear system

that transmits power of an input element to an output element through a variety of power transmission path. For example, a conventional planetary gear system comprises a sun gear, a planet carrier, and a ring gear. The forward and reverse rotation force input to the sun gear or a planet carrier is transmitted to the planet carrier, the ring gear or the sun gear and output as forward rotational force with a variety of gear ratios.

As another example of the conventional art, a one-way gear using a bevel gear and a clutch has been developed.

However, all of the above-described one-way gears are designed such that the input and output trains of the forward drive are different from those of the reverse drive. Therefore, the structure becomes more complicate than the general gear while the number of parts and the size is increased, making it difficult to be applied to a small-sized gear system such as a bicycle gear.

Although there have been a couple of one-way gears for a bicycle.

However, the conventional one-way gears are specifically designed only for the bicycle, they cannot be used or applied for other purposes.

BRIEF DESCRIPTION OF THE INVENTION The present invention has been made in an effort to solve the above-described problems of the prior arts.

It is an objective of the present invention to provide a one-way gear assembly that is designed in a simple structure having the small number of parts, thereby making it possible to be applied for a small-sized gear

system such as a bicycle gear.

It is another objective of the present invention to provide a one-way gear assembly that is designed such that the input and output trains (paths) of the forward drive are identical to those of the reverse drive.

It is still another objective of the present invention to provide a one- way gear assembly that can, when it is applied for a bicycle, release a forward output with respect to a reverse input, thereby realizing an identical power transmission to that of the conventional bicycle.

To achieve the above objectives, the present invention provides a one-way gear assembly comprising an inner gear provided with outer teeth, the inner gear being connected to one of input and output elements ; an outer gear provided with inner teeth, the outer gear being connected to the other one of the input and output elements ; a planet gear assembly having planet gears engaged between outer and inner teeth and a planet carrier supporting the planet gears; and a one-way output control device for 1) having the planet gear assembly rotate in a forward direction by allowing only a forward rotation of the planet gears around the inner gear when forward rotational force is input through one of the inner and outer gears and 2) having one of the inner and outer gears, which is connected to the output element, rotate in the forward direction by allowing a rotation of the planet gears on their own axes and suppressing a reverse rotation of the planet gear assembly when reverse rotational force is input through one of the inner and outer gears.

Preferably, the one-way output control device comprises

application/release means for 1) integrating the inner gear, the planet gear assembly and the outer gear as a single body to rotate the single body in the forward direction when the forward rotational force is input through one of the inner and outer gears and 2) releasing an engagement of the inner and outer gears to allow the inner gear, the planet gears and the outer gear to rotate on their own axes ; and one-way locking means for 1) allowing the planet gear assembly to rotate in the forward direction when the inner gear, the planet gear assembly and the outer gear are integrated by the application/release means and 2) suppressing the reverse rotation of the planet gear assembly when the inner gear, the planet gears and the outer gear rotate on their own axes.

According to an embodiment, the application/release means comprises a fixing member coupled on the planet carrier, a latch pole rotatably mounted on the planet carrier, and an elastic member disposed between the fixing member and the latch pole to bias the latch pole in a predetermined direction, wherein the latch pole is designed to 1) be engaged between the inner and outer gears when the forward rotational force is input through one of the inner and outer gears and 2) allow the rotation of the inner and outer gears when the reverse rotational force is input through one of the inner and outer gears.

According to another embodiment, the application/release means comprises a fixing shaft coupled to the planet carrier and located on an outer circumference of the planet gear, a latch pole rotatably coupled on the fixing shaft and biased by an elastic member in a radial direction, and

an inner teeth latch formed on the inner circumference of the planet gear, wherein the latch pole is designed to 1) be engaged with the inner teeth latch to suppress the rotation of the planet gear on its own axis when the forward rotational force is input through one of the inner and outer gears and 2) allow the rotation of the planet gear on its own axis when the reverse rotational force is input through one of the inner and outer gears.

Preferably, the one-way locking means comprises a latch rotatably mounted on an outer fixing ring, an engraved latch gear formed on the planet carrier, and an elastic member biasing the latch in a direction where the latch is engaged with the engraved latch gear, wherein the latch allows the forward rotation of the planet carrier when the inner gear and the planet gear assembly and the outer gear are engaged as the single body and suppresses the reverse rotation of the planet carrier when the inner gear, the planet gear, and the outer gear rotate on their own axes.

Further preferably, the one-way gear assembly may further comprise a wire extending from the latch, a locking release lever for releasing the engagement of the latch and the engraved latch gear by pulling the wire.

Preferably, the one-way gear assembly may further comprise bearings disposed between the inner gear, the outer gear and the planet carrier.

Further preferably, the one-way gear assembly may further comprise one-way locking release means for releasing a locking state of the planet gear assembly by the one-way locking means.

Alternatively, the one-way locking release means comprises a wire extending from the latch and a locking release lever for releasing the engagement of the latch and the planet gear assembly by pulling the wire.

According to one aspect, the input element may be a driving shaft of a pedal for a bicycle and the output element may be a sprocket.

According to another aspect, the input element may be a sprocket driven by a chain and the output element may be a wheel hub.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a front view of a one-way gear assembly according to a first embodiment of the present invention ; FIG. 2 is an exploded perspective view of a one-way gear assembly according to a first embodiment of the present invention; FIGS. 3 and 4 are respectively an exploded view and a sectional view of an application where a one-way gear assembly of the present invention is employed to a front wheel drive axle of a bicycle; FIG. 5 is a front view of an application where a one-way gear assembly of the present invention is employed to a rear wheel hub of a bicycle ; FIG. 6 is a front view of a one-way gear assembly according to a second embodiment of the present invention; and FIG. 7 is an exploded perspective view of a one-way gear assembly according to a second embodiment of the present invention.

DETAILD DESCRIPTION OF PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described more in detail in conjunction with the accompanying drawings.

Embodiment 1 FIGS. 1 and 2 show a first embodiment of the present invention.

As shown in the drawings, a one-way gear assembly of this embodiment comprises an inner gear 1, an outer gear 3, a planet gear assembly 5 engaged between the inner and outer gears land 3, and a one- way output control device for allowing the inner and outer gears 1 and 3 to output only the forward drive regardless of the input direction.

Referring to FIG. 1, the forward and reverse directions of the inner gear 1 are respectively clockwise and counterclockwise directions in the drawings, and the forward and reverse directions of the outer gear 3 are respectively counterclockwise and clockwise directions. The description relating to the direction will be based of the above directions.

The inner gear 1 is coupled to a driving shaft or an output shaft to synchronize therewith. That is, the inner gear 1 is provided at its inner circumference with a thread la coupled to the driving or output shaft and at its outer circumference with outer gear teeth 1b meshing with the planet gear assembly.

When the inner gear 1 is connected to the output shaft, the outer gear 3 is connected to the driving shaft, and when the inner gear 1 is connected to the driving shaft, the outer gear 3 is connected to the output shaft. The outer gear 1 is provided at its inner circumference with inner

gear teeth 3a meshing with the planet gear assembly 5. When applied to the bicycle, the outer gear 1 is provided at its outer circumference with a sprocket.

, The planet gear assembly engaged between the inner and outer gearsland 3 comprises small diameter planet gears 7 and a planet carrier 9 supporting the planet gears 7. Each of the planet gears 7 is rotatably installed by a coupling member such as a bolt 11 a and a nut 11b.

The one-way output control device is designed to, when the inner gear 1 or the outer gear 3 rotates in the forward direction, allows the planet gears 7 to rotate around the inner gear (i. e. , the planet carrier rotates on its own axis), thereby making the planet gear assembly 5 rotate in the forward direction. In addition, when the inner gear 1 or the outer gear 3 rotates in the forward direction, the one-way output control device suppresses the planet gears 7 to rotate around the inner gear in the reverse direction while allowing the planet gear assembly to rotate on its own axis in the forward direction. Accordingly, the one-way output control device controls the inner and outer gears 1 and 3 such that they can rotate in the forward direction.

To achieve the above operation of the one-way output control device, the present invention provides application/release means and one-way locking means.

The application/release means comprises a fixing member 13a mounted on the planet carrier 9 by a bolt 11a and a nut llb, a latch pole 13b rotatably mounted on the planet carrier 9, and an elastic member 13c

disposed between the fixing member 13a and the latch pole 13b to bias the latch pole in a direction.

By the application/release means, when the inner or outer gear is rotated in the forward direction, the latch pole 13b is engaged between the inner and outer gears 1 and 3, thereby integrating the inner gear 1, the planet gear assembly 5 and the outer gear 3 as a single body and rotating the single body in the forward direction.

In addition, when the inner or outer gear is rotated in the reverse direction, the latch pole 13b is released from the inner and outer gears 1 and 3 while overcoming the elastic force of the elastic member 13c. As a result, the planet gears 7 rotate on their own axes in the forward direction, and the outer or inner gear engaged with the planet gears 7 rotates on its own axis in the forward direction. However, for the forward rotation of the planet gears 7, the reverse rotation of the planet carrier 9 on its own axis should be suppressed.

Therefore, in the present invention, the one-way locking means is provided. That is, the one-way locking means allows for the forward rotation of the planet carrier 9 when the inner gear 1, the planet gear assembly 5 and the outer gear 3 are integrally rotated as one body, but suppresses the reverse rotation of the planet carrier 9 when the planet carrier 9 when the planet gears 7 rotates on its own axis in the forward direction.

Preferably, the one-way locking means comprises a latch 17 rotatably supported on an outer fixing ring 15 (see FIGS. 3 and 4), an

engraved latch gear 19 formed on the planet carrier 9, and an elastic member 21 biasing the latch 17 engaging with the engraved latch gear 19.

When the inner gear 1, the planet gear assembly 5, and the outer gear 5 rotate together in the forward direction by the operation of the application/release means, the latch 17 is released from the engraved latch gear 19 while overcoming the elastic force of the elastic member 21 by the pushing force of the planet carrier 9, thereby enabling the rotation of the planet carrier 9 in the forward direction.

In addition, when the inner gear 1, the planet gears 7 and the outer gear 3 are allowed to rotate on their own axes by the application/release means, since the latch 17 maintains its engagement state with the engraved latch gear 19, the reverse rotation of the planet carrier 9 is suppressed, thereby enabling the forward rotation of the planet gears 7.

In addition, if required, one-way locking release means may be provided to maintain the release state of the latch 17 and the engraved latch gear 19, thereby releasing the one-way output.

The one-way locking release means comprises a wire 23 extending from the latch 17 and a locking release lever 25 for releasing the latch 17 from the engraved latch gear 19 by pulling the wire 23.

In FIGS, 1 and 2, the reference numeral 38 that is not described above indicates bearings. The bearings 38 are disposed between the inner gear 1, the outer gear 3 and the planet carrier 9 to enhance the rotational operations of them.

The operation of the one-way gear assembly of this embodiment will

be described hereinafter. -.

FIGS. 3 and 4 shows an application example where the one-way gear assembly of the present invention is employed to a bicycle.

The reference numeral 27 indicates a main frame housing of the bicycle. A pedal-driving shaft is rotatably mounted on the mainframe housing. The reference numerals 29,29a and 29b indicate a pedal, a connecting rod, and a pedal driving shaft, respectively.

The outer fixing ring 15 for rotatably supporting the latch 17 is coupled on the main frame housing 27.

As described above, the one-way gear assembly of the present invention is mounted on the driving shaft 29b by the thread la of the inner gear 1 coupled on the driving shaft 29b.

In this case, the driving force is input to the inner gear 1, and then output through the sprocket 33 integrally formed around the outer circumference of the outer gear 3.

Describing the operation of the present invention more in detail, when a} user operates the pedal 29 to rotate the driving shaft 29b in the forward direction. (in the clockwise direction), the inner gear 1 rotates in the forward direction and the latch pole 13b is engaged between the inner and outer gears 1 and 3, thereby synchronizing the inner gear 1, the planet gear assembly 5 and the outer gear 3 as a single body. The single body rotates in the forward direction.

In addition, the latch 17 is released from the engraved latch gear 19 while overcoming the elastic force of the elastic member 21, thereby

enabling the forward rotation of the planet carrier 9.

Accordingly, the sprocket 33 integrally formed on the outer circumference of the outer gear 3 rotates in the forward direction, and thereby a chain 31 rotates in the forward direction. As a result, the bicycle moves forward.

In addition, when the user operates the pedal 29 to rotate the driving shaft 29b in the reverse direction (in the counterclockwise direction), the inner gear 1 rotates in the reverse direction and the latch pole 13b is released from the inner and outer gears 1 and 3 while overcoming the elastic force of the elastic member 13c. Accordingly, the inner gear 1 rotates in the reverse direction, the planet gears 7 rotate on their own axes in the forward direction, and the outer gear 3 rotates in the forward direction.

As a result, the sprocket 33 rotates in the forward direction to rotate the chain 31 in the forward direction. As a result, the bicycle moves forward.

At this point, the latch 17 of the one-way locking means is engaged with the engraved latch gear 19 to suppress the reverse rotation of the planet carrier, i. e. , the reverse rotation of the planet gears 7 around the inner gear 1.

Particularly, when the one-way gear assembly of the present invention is employed to the driving shaft of the bicycle and the pedal is operated in the reverse direction, the rotational speed of the inner gear 1 is reduced through the planet gears 7 while the driving force is increased.

Accordingly, the bicycle is very useful as a mounting bike.

As another example, the latch 17 can be designed to be a normal release state by operating the locking release lever 25 of the one-way locking release means. In this case, when the inner gear 1 is driven in the reverse direction, the planet gears rotate on their own axes and around the inner gear 1. As a result, the planet gear assembly 5 rotates on its own axis along the inner teeth 3a of the outer gear 3, thereby idling the outer gear 3. Accordingly, the normal power transmission of the conventional bicycle is realized.

FIG. 5 shows a one-way gear assembly of the present invention, which is employed to a rear wheel hub of a bicycle.

The reference numerals 35 and 37 indicate a rear wheel hub of the bicycle and a rear wheel sprocket, respectively.

Driving force is input through the chain 31, the sprocket 37 and the outer gear 3. The input driving force is output through to hub 35 via the inner gear 3.

In FIG. 5, the forward direction of the outer gear 3 is the clockwise direction. The gear structure of FIG. 5 is, identical to when the gear structure of FIG. 1 is rotated by 180°.

When the user operates the pedal 29 to rotate the chain 31 in the forward direction (in the clockwise direction), the outer gear 3 rotates in the forward direction and the latch pole 13b is engaged between the inner and outer gears 1 and 3, thereby synchronizing the inner gear 1, the planet gear assembly 5 and the outer gear 3 in a single body. The single body

rotates in the forward direction.

In addition, the latch 17 is released from the engraved latch gear 19 while overcoming the elastic force of the elastic member 21, thereby enabling the forward rotation of the hub 35 coupled to the inner gear 1. As a result, the rear wheel rotates clockwise to advance the bicycle.

In addition, when the user operates the pedal 29 to rotate the chain 31in the reverse direction (in the counterclockwise direction), the outer gear 3 rotates in the reverse direction and the latch pole 13b is released from the inner and outer gears 1 and 3. Accordingly, the outer gear 3 rotates in the reverse direction, the planet gears 7 rotate on their own axes in the forward direction, and the inner gear 1 rotates in the forward direction. As a result, the bicycle moves forward.

At this point, the latch 17 of the one-way locking means is engaged with the engraved latch gear 19 to suppress the reverse rotation of the planet carrier, i. e. , the reverse rotation of the planet gears 7 around the inner gear 1.

Particularly, when the one-way gear assembly of the present invention is employed to the hub of the bicycle and the pedal is operated in the reverse direction, the rotational speed of the outer gear 3 is reduced through the planet gears 7 while the driving force is increased.

Accordingly, the bicycle is very useful as a mounting bike.

Embodiment 2 FIGS. 6 and 7 shows a second embodiment of the present invention.

As shown in the drawings, a one-way gear assembly of this embodiment comprises an inner gear 1, an outer gear 3, a planet gear assembly 5 engaged between the inner and outer gears land 3, and a one- way output control device for allowing the inner and outer gears 1 and 3 to output only the forward drive regardless of the input direction.

In FIG. 6, the forward and reverse directions of the inner gear 1 are respectively clockwise and counterclockwise directions, and the forward and reverse directions of the outer gear 3 are respectively counterclockwise and clockwise directions. The description relating to the direction will be based of the above directions.

As in the first embodiment, a one-way output control device is designed to, when the inner gear 1 or the outer gear 3 rotates in the forward direction, allows the planet gears 7 to rotate around the inner gear (i. e. , the planet carrier rotates on its own axis), thereby making the planet gear assembly 5 rotate in the forward direction. In addition, when the inner gear 1 or the outer gear 3 rotates in the forward direction, the one-way output control device suppresses the planet gears 7 to rotate around the inner gear in the reverse direction while allowing the planet gear assembly to rotate on its own axis in the forward direction.

To achieve the above operation, this embodiment has also one-way locking means identical to that of the first embodiment, description of which will be omitted in this embodiment.

This embodiment is actually identical to the first embodiment except for the application/release means, which will be described more in detail

hereinafter.

The application/release means comprises a fixing shaft 39a coupled to the planet carrier 9 by a bolt lla and a nut 11b, a latch pole 39b rotatably mounted on the fixing shaft 39a, and an elastic member 39c disposed between the fixing shaft 39a and the latch pole 39b to bias the latch pole 39a in one direction.

The planet gears 7 are rotatably coupled on an outer circumference of the fixing shaft 39a. By the biasing force of the elastic member 39c, the latch pole 39b remains the normal engagement state with an inner teeth latch 41 formed on an inner circumference of the planet gear 7.

Accordingly, the inner or outer gear is driven in the forward direction and the planet gears 7 receive reverse rotational force. At this point, since the latch pole 39b is engaged with the inner teeth latch 41, the reverse rotation of the planet gears 7 on their own axes is suppressed. As a result, the inner gear 1, the planet gear assembly 5, and the outer gear 3 rotate in the forward direction as a single body.

In addition, when the inner or outer gear is driven in the reverse direction, the planet gears 7 receive the forward rotational force. At this point, since the latch pole 39b overcomes the elastic member 39c to release from the inner teeth latch 41, the planet gears 7 rotate on their own axes in the forward direction. As a result, the inner or outer gear engaged with the planet gears 7 rotates in the forward direction. At this point, the planet gears 7 receive the reverse rotational force around the inner gear 1.

However, this can be solved by the one-way locking means suppressing

the rotation of the planet carrier 9.

Since the operation of this embodiment is identical to that of the first embodiment, the detailed description thereof will be omitted herein.

INDUSTRIAL APPLICABILITY As described above, the one-way gear assembly of the present invention is designed not to transmit forward rotational force of an inner gear to an outer apparatus but to output the same to an outer gear in the same apparatus, thereby simplifying the structure of the apparatus to reduce the manufacturing costs.

In addition, the one-way gear of the present invention outputs rotational force through the inner gear with respect to the forward and reverse input rotational force of the outer gear. Furthermore, by converting the directions of the application/release means and the one-way locking means disposed between the inner and outer gears, the rotational direction of the output gear can be converted in a desired direction.

Accordingly, the one-way gear of the present invention can be used as "a power transmission system for outputting rotational force of an outer gear in one way with respect to forward and reverse input rotational force of an inner gear"or"a power transmission system for outputting rotational force of an inner gear in one way with respect to forward and reverse input rotational force of an outer gear." For example, when the one-way gear assembly is applied to a rear wheel hub of a bicycle, it can output the forward rotational force with

respect to both of the forward and reverse input by a pedal.

Particularly, when the one-way gear is applied to the driving shaft of the pedal, since the reverse driving force is input through the pedal, a speed reduction occurs, whereby the driving force is increased. Therefore, the bicycle employing the one-way gear assembly of the present invention is more useful as a mounting bike or a non-paved road bike. In addition, when the one-way gear of the present is applied to a rear wheel hub, since the speed is increased during the reverse drive, the bicycle can be useful as a racing bike or a paved road bike.