BICYCLE DRIVING DEVICE

摘要

The present invention relates to a bicycle driving device wherein a movement interval of crank arms connected to a crank shaft for driving the bicycle may be controllable so that a user may drive the bicycle smoothly and effectively. In a bicycle driving device including a driving section connected to a chain for transmitting a rotation force to the wheels, crank arms coupled with a side surface and the other side surface of the driving section for allowing the smooth rotation of the driving section, and pedals coupled with the crank arms for the feet of a user to be placed thereon, the crank arms are formed of first crank arms coupled with the driving sections and second crank arms rotatively coupled with the first crank arms, wherein the first crank arms and the second crank arms are coupled by variable coupling elements. According to the present invention, first, the bicycle driving device for smoothly driving a bicycle comprises the crank arms for rotating the driving sections, and the crank arms includes the second crank arms rotatively coupled with the first crank arms, so that the rotation radius of the crank arms, which rotate by the feet of the user, may be effectively controlled, thereby driving the bicycle smoothly and effectively. Secondly, the lengths of the first crank arms and the second crank arms are extended in the longitudinal direction so that rotation force may be effectively transmitted to the driving section when the user wants to transmit the rotation force of the second crank arms to the driving section by actively rotating the pedals of the second crank arms by his feet. Conversely, the rotation radius of the crank arms rotating with respect to the driving section is minimized by the variable coupling elements, which connect the first crank arms to the second crank arms, so that the bicycle may be effectively driven, when the user is at a position in which he does not want to transmit the rotation force to the driving section through the movement of the second crank arms. Thirdly, the crank arms are coupled with the driving section for transmitting the rotation force to the driving section in such a manner that the rotation radius of the crank arms is minimized. Therefore, the driving section is effectively rotated in response to the rotation of the crank arms while preventing unnecessary manipulation by the user who rotates the crank arms, thereby preventing the user from feeling exhausted easily. Fourthly, the second crank arms and the pedals may be conveniently coupled in use after separating the pedals from conventional crank arms. Therefore, the bicycle driving device may be conveniently and effectively used without coupling any complicated equipment, reducing installation costs thereof and exhibiting cost reduction. Even when the cranks arms are damaged partially during use, the damaged parts may be conveniently exchanged with new ones, thereby increasing the convenience of use and reducing costs.