WO1998006622A1

WO1998006622A1 - Bicycle forward driving apparatus

Info

Publication number: WO1998006622A1
Application number: PCT/KR1997/000047
Authority: WO
Inventors: Chun Kill Park
Original assignee: LEE JUN HYUNG
Current assignee: LEE JUN HYUNG
Priority date: 1996-08-08
Filing date: 1997-03-25
Publication date: 1998-02-19
Anticipated expiration: 1999-02-08
Also published as: KR19980010550U; AU2179997A; CN1173446A; KR200144371Y1

Abstract

A bicycle forward driving apparatus includes a driven sprocket wheel which rotates by receiving a pedal's driving force; an inner sprocket wheel separably coupled to a rear wheel's hub axle; first one-direction rotation means installed between the driven sprocket wheel and inner sprocket wheel so that its rotation force is transmitted to the inner sprocket wheel only during the driven sprocket wheel's forward rotation; a plurality of intermediate gears engaged between the driven sprocket wheel and inner sprocket wheel for transmitting rotation force; a support bracket for rotatably fixing the plurality of intermediate gears; a fixed cylinder inserted into the rear wheel's fixed axle; and second one-direction rotation means installed between the fixed cylinder and support bracket so that only the support bracket rotates forward. Accordingly, the apparatus enables a bicycle to be driven forward even during the pedal's reverse rotation, as well as it is freely shifted forward/backward.

Description

BICYCLE FORWARD DRIVING APPARATUS

Technical Field

The present invention relates to a bicycle forward driving apparatus by which a bicycle is driven forward even when its pedal is driven reversely.

Background Art

Generally speaking, a bicycle's driving apparatus is formed with a driving sprocket wheel installed on the side of the pedal, a driven sprocket wheel installed on the side of the rear wheel, and a chain which connects them. A one-direction clutch for rotating the rear wheel only forward is installed on the driven sprocket wheel of the rear wheel .

When the pedal is rotated forward, its rotation force is transmitted to the rear wheel by the one- direction clutch so that the bicycle is driven forward. When the pedal is stopped or rotated reversely, the pedal races while the rotation force is not transmitted to the rear wheel by the one-direction clutch but. In this situation, the bicycle is continuously driven forward due to its inertia.

Such a bicycle forward driving apparatus is designed to be driven forward only by the pedal's forward rotation so that the pedal's rolling operation is simple and legs become exhausted during long-time running because the pedal is rotated continuously only in one direction.

For the relax of the legs during running, the pedal rolling operation should be stopped or rotated reversely. The pedal ' s reverse rotation causes power loss because in this state, the force is not transmitted to the rear wheel but the pedal races.

In order to compensate for such drawbacks, there was developed an apparatus for driving the bicycle forward even during the pedal's reverse rotation. The bicycle forward driving apparatus disclosed in Korean Patent

Publication No. 95-13589 includes a body frame to which a fixing bracket with a pulley is fastened, a traveling portion for transmitting the driving force of the pedal axle rotatably fastened to the center of the body frame to the driving sprocket, an invertedly driving portion attachably/detachably fastened to the traveling portion and for inverting the reverse rotation or racing of the pedal axle into the forward rotation which is then transmitted to the driving sprocket, and a switching lever portion for attaching or detaching the invertedly driving portion to or from the traveling portion according to the rider's intention.

In this construction of the forward driving apparatus, when the rider operates the lever of the switching lever portion during running, the invertedly driving portion is coupled to the traveling portion, which is converted and rotated forward during the pedal's reverse rotation by the invertedly driving portion. Through this process, the bicycle can run forward even during the pedal's reverse rotation.

However, when the bicycle is supposed to run forward with the pedal rotated reversely, the lever of the switching lever portion must be operated by the rider so that the invertedly driving portion is coupled to the traveling portion. When the bicycle is to be driven forward with the pedal rotated forward, the lever must be operated again so that the invertedly driving portion is released from the traveling portion. This procedure inconveniences the bicycle's operation with complicated lever manipulation.

In addition, the apparatus is made so that during the transmission of the rotation force to the traveling portion via the invertedly driving portion, the rotation ratio is reduced not to maintain the same traveling speed as in the pedal's forward rotation. Furthermore, the invertedly driving portion and switching lever portion are very complicated and have so many components, increasing the number of assembly process, which decreases the productivity and raises the production cost .

Disclosure of Invention Accordingly, the present invention is directed to a bicycle forward driving apparatus that substantially obviates one or more of the problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a bicycle forward driving apparatus by which the bicycle can be driven forward only with the pedal's forward or reverse rotation, without an additional manipulation of a lever.

Another object of the present invention is to provide a bicycle forward driving apparatus which is formed in one set and fastened to the hub axle or detached from it so that the apparatus assembly and disassembly are performed to facilitate its repairing, and that the process of assembly and component management are carried out efficiently in the manufacturing of bicycles.

Still another object of the present invention is to provide a bicycle forward driving apparatus which maintains the same traveling speed so that even the pedal's reverse rotation involves the rotation ratio of 1:1 which is the same as that of the forward rotation.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings .

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described, there is provided a bicycle forward driving apparatus comprising: a driven sprocket wheel which rotates by receiving a pedal's driving force; an inner sprocket wheel separably coupled to a rear wheel's hub axle; first one-direction rotation means installed between the driven sprocket wheel and inner sprocket wheel so that its rotation force is transmitted to the inner sprocket wheel only during the driven sprocket wheel's forward rotation; a plurality of intermediate gears engaged between the driven sprocket wheel and inner sprocket wheel for transmitting rotation force; a support bracket for rotatably fixing the plurality of intermediate gears; a fixed cylinder inserted into the rear wheel's fixed axle; second one- direction rotation means installed between the fixed cylinder and support bracket so that only the support bracket rotates forward. The bicycle forward driving apparatus further comprises locking release means for driving the second one-direction rotation means so that the support bracket is selectively rotated reversely.

The second one-direction rotation means comprises a ratchet wheel formed in the support bracket, and a ratchet elastically installed on the fixed cylinder to appear and disappear. The locking release means comprises a rotatable body installed to be engaged with the ratchet and having a circular projections formed on one side and protruded toward the inner sprocket wheel; and a plurality of cams formed on the inner sprocket wheel and guiding the circular projections so that the rotatable body is rotated at a predetermined angle according to the forward/backward rotation of the inner sprocket wheel. The inner sprocket wheel is detachable from the hub axle with a screw, and the fixed cylinder is inserted into the fixed axle and fastened with a nut.

It is to be understood that both the foregoing general description and the driven detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Brief Description of Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention. In the drawings :

FIG. 1 is a sectional view of a bicycle forward driving apparatus of the present invention; FIG. 2 is an enlarged sectional view taken along line C-C of FIG. 1; FIG. 3 is an exploded perspective view of the ratchet and rotatable body of the bicycle forward driving apparatus of the present invention;

FIGS. 4A and 4B are partially enlarged sectional views taken along line D-D of FIG. 1, showing the locking release operation of the ratchet;

FIG. 5 is an elevation view which shows the cam shape of the inner sprocket wheel in the bicycle forward driving apparatus of the present invention; FIGS. 6A-6D illustrate the operations between the ratchet and sprocket wheel of the present invention; FIGS . 7A and 7B show another embodiment of the ratchet release means of the present invention, showing the locking release operation of the ratchet; and FIG. 8 shows the operation of the rotatable plate in the ratchet release means of the present invention.

Best Mode for Carrying Out the Invention

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings.

Referring to FIG. 1, a first one-direction rotating portion is installed between a driven sprocket wheel 21 connected with a pedal and chain (not shown) to be engaged therewith, and inner sprocket wheel 24 detachably screw-fastened to hub axle 23 of rear wheel 22.

As shown in FIGS. 1 and 2, the first one-direction rotating portion comprises ratchet wheel 25 formed in driven sprocket wheel 21, and ratchet 27 installed in inner sprocket wheel 24 elastically with spring 26 to appear and disappear. It is constructed so that the rotation force is transmitted to inner sprocket wheel 24 only when driven sprocket wheel 21 rotates forward.

Between driven sprocket wheel 21 and inner sprocket wheel 24, there is a plurality of intermediate gears 28 fixed rotatably to support bracket 29. These gears reverse the rotation direction of driven sprocket wheel 21, and transmit it to inner sprocket wheel 24. The rotation ratio of sprocket wheel 21 and inner sprocket wheel 24 is preferably 1:1.

Meanwhile, fixed cylinder 31 is inserted into the fixed axle 30 of rear wheel 22, and fastened by nut 32. A second one-direction rotating portion is installed between fixed cylinder 32 and support bracket 29. As shown in FIGS. 1 and 4A, the second one-direction rotating portion comprises ratchet wheel 33 formed in support bracket 29, and ratchet 35 installed elastically with spring 34 to appear and disappear. This second one- direction rotating portion is made only to rotate support bracket 29 forward.

A locking release means for driving the second one- direction rotating portion is provided so that support bracket 29 is selectively rotated reversely. The locking release means, as shown in FIGS. 3, 4 and 5, has a rotatable body 36 installed in ratchet 35 and including a circular projection 36a protruded toward inner sprocket wheel 24, and a plurality of cams 37 for guiding circular projection 36a so that rotatable body 36 rotates at a predetermined angle when inner sprocket wheel 24 rotates forward or reversely.

Cams 37 are protruded from inner sprocket wheel 24, and disposed along its circumference. They maintain an interval through which circular projection 36a of rotatable body 36 passes. The confronted faces of one cam 30 and its adjacent cam form a slanted passage 37a so that circular projection 36a is led above or under cam 37 according to the rotation direction of inner sprocket wheel 24. When inner sprocket wheel 24 rotates forward, circular projection 36a is guided to be located under cam 37 through slanted passage 37a between cams 37. When inner sprocket wheel 24 rotates reversely, circular projection 36a is located above cam 37 through slanted passage 37a.

Referring to FIGS. 7A, 7B and 8, another embodiment of the locking release means is made so that rotatable plate 40 is installed to be rotated centering on pin 41, adjacent to ratchet 35. The lower end of spring 34 of ratchet 35 is interrupted by one end of rotatable plate 40.

Rotatable plate 40 rotates left and right at a predetermined angle according to the rotation direction of inner sprocket wheel 24. A plurality of protrusions 42 are disposed on the side of inner sprocket wheel 24 at predetermined intervals along its circumference. Part of the end of rotatable plate 40 is inserted between protrusions 42.

With this configuration, when inner sprocket wheel 24 rotates forward, rotatable plate 40 does not rotate clockwise any more while in the state of the solid line of FIG. 8, and maintains the position (see FIG. 7A) of the solid line so that ratchet 35 performs its own function. When inner sprocket wheel 24 rotates reversely, rotatable plate 40 rotates counterclockwise by protrusions 42 like the virtual line so that spring 34 hooked by one end of the plate is pulled downward. By doing so, ratchet 35 is inserted into fixed cylinder 31, as in FIG. 7B, so as to release the locking state and thus allow support bracket 29 to rotate reversely.

With such construction of the present invention, a bicycle runs forward when its pedal rotates either forward or reversely. If the pedal rotates forward and thus driven sprocket wheel 21 rotates forward (in the direction of arrow "a" of FIG. 5) as in FIGS. 1, 2, and 4A, the rotation force is transmitted to inner sprocket wheel 24 by ratchet wheel 25 and ratchet 27 so that, the sprocket wheel and hub axle 23 of the rear wheel are rotated to enable the bicycle to run forward. Here, intermediate gears 28 rotate in the same direction as support bracket 29 because the rotation directions of driven sprocket wheel 21 and inner sprocket wheel 24 are the same. The gears are rotatable by ratchet wheel 33 and ratchet 35 if inner sprocket wheel 24 rotates forward (in the direction of arrow "c") as in FIG. 4A.

When the pedal is rotated reversely and thus driven sprocket wheel 21 is rotated reversely (in the direction of arrow "b" of FIG. 2) , the rotation force is not directly transmitted to inner sprocket wheel 24 by ratchet wheel 25 and ratchet 27 but the rotation direction is converted through intermediate gears 28 so as to rotate inner sprocket wheel 24 forward. Therefore, hub axle 23 of the rear wheel is rotated forward even when the pedal is rotated reversely, so that the bicycle can be driven forward. Because the rotation ratio of the driven sprocket wheel 21 and inner sprocket wheel 24 is 1:1, the pedal's reverse rotation maintains the same traveling speed as that of the forward rotation. Here, driven sprocket wheel 21 and inner sprocket wheel 24 are rotated in the opposite directions, and support bracket 29 cannot be rotated in the direction of arrow "d" by ratchet wheel 33 and ratchet 35 so that intermediate gears 28 transmit only the rotation force at its original position.

In another aspect, the bicycle forward driving apparatus of the present invention enables the bicycle to move forward or backward by rotating the front and rear wheels with the pedal not stepped on. In case that: rear wheel 22 is rotated forward to allow the bicycle to run forward, the rotation force is not transmitted to driven sprocket wheel 21 by ratchet wheel 25 and ratchet 27 because inner sprocket wheel 24 fixed to hub axle 23 rotates forward (in the direction of arrow "a") as in FIGS. 1 and 2. In this state, support bracket 29 rotates forward in the direction of arrow "c" as in FIG. 4A because intermediate gears 28 receive the rotation force of inner sprocket wheel 24 and race with driven sprocket wheel 21 which stops.

Here, support bracket 29 is rotatable by ratchet wheel 33 and ratchet 35 so that the bicycle runs forward. Circular projection 36a of rotatable body 36 engaged with ratchet 35 is located under cam 37 as in FIG. 9A, and, when cam 37 of inner sprocket wheel 24 rotates forward in the direction of arrow "a", the projection is led under cam 37, as shown with the virtual line, not toward passage 37a, because of its curved surface. For this reason, rotatable body 36 is not engaged with ratchet 35. In case the bicycle is to be moved backward, if hub axle 23 of rear wheel 22 and inner sprocket wheel 24 are rotated reversely (in the direction of arrow "b") as shown in FIGS. 1 and 2, the rotation force is transmitted to driven sprocket wheel 21 by ratchet wheel 25 and ratchet 27 so that driven sprocket wheel 21 is rotated reversely. Because driven sprocket wheel 21 and inner sprocket wheel 24 are rotated in the same direction, intermediate gears 28 and support bracket 29 are rotated reversely therealong.

When inner sprocket wheel 24 is rotated reversely, rotatable body 36 is engaged with ratchet 35 to enable support bracket 29 to rotate reversely. If cam 37 of inner sprocket wheel 24 is rotated in the direction of arrow "b" while circular projection 36a of rotatable body 36 is led under cam 37 as in FIG. 6B, the projection is led to the inner surface of passage 37a along the curved surface of cam 37 when it is located at passage 37a between cams 37, and finally the projection is located above cam 37.

As circular projection 36a of rotatable body 36 is shifted, rotatable body 36 rotates clockwise centering on pin 35a of ratchet 35 as in FIG. 4B. In addition, when ratchet 35 rotates clockwise, spring 34 is pressed to be inserted into fixed cylinder 31 so that support bracket 29 is freely rotatable reversely (in the direction of arrow "d") and therefore the bicycle can be moved backward .

As shown in FIG. 6C, even though inner sprocket wheel 24 is continuously rotated reversely and circular projection 36a is located at passage 37a between cams 37, the projection is led to the top of the cams not to passage 37a so that the bicycle continuously moves backward. As shown in FIG. 6D, if inner sprocket wheel 24 rotates forward (in the direction of arrow "a"), circular projection 36a is led under cam 37 through passage 37a between cams 37 as shown with the virtual line so that rotatable body 36 and ratchet 35 return to the original place by the spring 34 's resilient force as in FIG. 4A to perform their own functions.

The bicycle forward driving apparatus of the present invention is constructed so that its assembly and disassembly are facilitated. Specifically, inner sprocket wheel 24, driven sprocket wheel 21, intermediate gears 28, support bracket 29, and fixed cylinder 31 are formed in one set so that their assembly can be easily performed when inner sprocket wheel 24 is screw-fastened to hub axle 23 and at the same time fixed cylinder 31 is inserted into fixed axle 30 and then fastened by nut 32. In the reverse order, the disassembly is easily performed by separating nut 32 and then inner sprocket wheel 24 from hub axle 23. This facilitates its repairing.

As described above, the bicycle forward driving apparatus of the present invention enables a bicycle's forward driving even during the pedal's reverse rotation, as well as free forward/backward shifting of the bicycle. In addition, the apparatus' assembly and disassembly are performed simply to facilitate its repairing. Furthermore, the process of assembly and component management are carried out efficiently in the manufacturing of bicycles.

It will be apparent to those skilled in the art that various modifications and variations can be made in the bicycle forward driving apparatus of the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

Claims :

1. A bicycle forward driving apparatus comprising: a driven sprocket wheel which rotates by receiving a pedal's driving force; an inner sprocket wheel separably coupled to a rear wheel's hub axle; first one-direction rotation means installed between the driven sprocket wheel and inner sprocket wheel so that its rotation force is transmitted to the inner sprocket wheel only during the driven sprocket wheel's forward rotation; a plurality of intermediate gears engaged between the driven sprocket wheel and inner sprocket wheel for transmitting rotation force; a support bracket for rotatably fixing the plurality of intermediate gears; a fixed cylinder inserted into the rear wheel's fixed axle; and second one-direction rotation means installed between the fixed cylinder and support bracket so that only the support bracket rotates forward.

2. The apparatus as claimed in claim 1, further comprising locking release means for driving the second one-direction rotation means so that the support bracket is selectively rotated reversely.

3. The apparatus as claimed in claim 2, wherein the second one-direction rotation means comprises a ratchet wheel formed in the support bracket, and a ratchet elastically installed on the fixed cylinder to appear and disappear.

4. The apparatus as claimed in claim 3, wherein the locking release means comprises a rotatable body installed to be engaged with the ratchet and having a circular projections formed on one side and protruded toward the inner sprocket wheel; and a plurality of cams formed on the inner sprocket wheel and guiding the circular projections so that the rotatable body is rotated at a predetermined angle according to the forward/backward rotation of the inner sprocket wheel .

5. The apparatus as claimed in claim 3, wherein the locking release means comprises a rotatable plate rotatably installed centering on a pin adjacent to the ratchet, one end of the plate interrupting the lower end of a spring; and a plurality of protrusions disposed along the inner sprocket wheel's circumference on its sidewall at predetermined intervals, and for rotating the rotatable plate to the left and right according to the rotation direction of the inner sprocket wheel.

6. The apparatus as claimed in claim 1, wherein the inner sprocket wheel is detachable from the hub axle with a screw, and the fixed cylinder is inserted into the fixed axle and fastened with a nut.