The present invention allows a user to ride a bicycle while lying with his/her face down, thereby lowering the center of weight and improving the driving stability, increasing the velocity by reducing the air resistance during driving, and increasing the generation of thrust by easily transferring the force of the user to pedals, and comprises: a frame provided with a front wheel and a rear wheel such that the user can ride while lying with his/her face down; and an acceleration means installed on the rear wheel and generating power and acceleration according to pedaling.
1 . A bicycle comprising:
a frame on which a front wheel and a rear wheel are mounted to allow a user to ride while lying with a face of the user down; and
an acceleration device mounted on the rear wheel to generate a power and perform acceleration according to pedaling; wherein the acceleration device includes:
a main bracket mounted on ends of rear and bottom tubes;
a pedal shaft provided on the main bracket with a one-way bearing interposed between to transmit a power in a forward direction and perform idling in a rearward direction;
pedals coupled to both sides of the pedal shaft, respectively;
a driver gear provided on one side of the pedal shaft to generate the power through a rotation of the pedal shaft;
a switching shaft provided on an auxiliary bracket, which is maintained between main brackets by a supporter, with a bearing interposed therebetween;
a mediating gear provided on one side of the switching shaft so as to be engaged with the driver gear;
an acceleration gear mounted on a lateral side of the mediating gear;
a driving gear provided on the pedal shaft, which is provided on a lateral side of the driver gear, with a bearing interposed therebetween so as to be engaged with the acceleration gear to output an accelerated power; and
a hub fixed to the driving gear and mounted at the ends of the rear and bottom tubes to drive the rear wheel,
wherein the driver gear, the switching shaft, the mediating gear, the acceleration gear and the driving gear are provided within the hub, and the pedal shaft passes through central portions of the hub, the main bracket and the rear wheel.
2 . The bicycle of claim 1 , wherein the frame includes:
a stanchion tube having a lower end on which the front wheel is mounted;
a head tube on which the stanchion tube is rotatably mounted;
a top tube connected to an upper rear side of the head tube;
a down tube connected to a front lower end of the top tube so as to be inclined rearward;
a center tube connected to rear ends of the top tube and the down tube in a longitudinal direction;
a rear tube connected to an upper end of the center tube so as to be inclined downward to a rear side of the center tube; and
a bottom tube extending horizontally from a lower end of the center tube to the rear side of the center tube so as to be connected to the lower end of the center tube.
3 . The bicycle of claim 2 , further comprising:
a flat part formed on a top surface of the top tube to stably support chest and stomach regions, which correspond to an upper body of the user, such that the chest and stomach regions consecutively make contact with the flat part;
a shoulder hook formed on a front side of the top tube to receive and support both shoulders of the user who lies with the face of the user down;
a seat part protruding upward from a rear end of the top tube so as to be inclined rearward to support a hip portion of the user; and
a handle mounted on both sides of an upper end of the stanchion tube so as not to interfere with the head tube.
4 . The bicycle of claim 1 , wherein a cap is further mounted on an outside of the frame.