| 摘要 |
<p>The present invention relates to a retractable crank and a bicycle using the same. According to the present invention, the retractable crank comprises a hollow rotary shaft combined with a rotary body; a crank shaft combined with the rotary shaft by penetrating; a par iof fixing arms mutually faced across the crank shaft and spaced from each other; a pair of movable arms combined with each fixing arm to be able to be operated in a telescopic form and having cam guides protruding from the insides thereof; a pair of cylinder cam having guide grooves or guide protrusions formed on the outer circumferential surfaces thereof, wherein the guide grooves have the cam guide combined therewith and sliding therein, and rotating inside the fixing arms, respectively; two pairs of bevel gears combined with the cylinder cams and both ends of the crank shaft and rotated by being interlocked with the cylinder cams and the ends of the crank shaft; an idle bevel gear combined with the rotary shaft to be rotated by being interlocked with the bevel gear which is combined with one of the cylinder cams; and a pair of pedals combined with each end of the movable arms to be able to rotate on the axis thereof.</p> |
