THREE-WHEEL BICYCLE

To provide a three-wheel bicycle that can prevent from falling, and keep in a self-standing state while not consistently excessively narrowing an interval between three-point supported two front wheels as viewed from the front side and that can easily turn on a dime and further can lower the center of gravity.SOLUTION: A three-wheel bicycle includes: a handle shaft rotatably inserted into a cylindrical handle frame body; a steering cylindrical body formed in a substantially cylindrical shape and having an upper end portion fixed to a lower end portion of the handle shaft to be disposed vertically, and a lower end portion with an inner peripheral wall on which an internal gear is formed; a parallel link attached on a front side of the steering cylindrical body; the internal gear rotatable in synchronization with the handle shaft; an external spur gear engageable with the internal gear; and a steering link provided with a drive link connected to the external spur gear. The two front wheels turn at a turning angle obtained by adding: a turning angle generated by the parallel link that is connected to the handle shaft so as to be integrally rotatable in a lateral direction; and a turning angle generated by the steering link that rotates by a gear ratio between the external spur gear and the internal gear at a rotation angle different from that of the handle shaft.SELECTED DRAWING: Figure 6 【課題】三輪自転車の３点支持の前２輪の正面視からの間隔を常時狭くしすぎず三輪自転車の転倒を防止し自立させ、かつ三輪自転車の小回りを容易にでき、さらに重心を低くできる三輪自転車を提供することを課題とする。【解決手段】筒状のハンドルフレーム体内に回転自在に挿通させたハンドル軸と、上端部を前記ハンドル軸の下端部に固定して垂設させた、下端部の内周壁部に内歯が形成された略筒状体の操舵筒状体と、前記操舵筒状体の前側に取り付けられ平行リンクと、前記ハンドル軸と同調して回転する内歯と、その内歯にかみ合う外歯平歯車と、前記外歯平歯車と連結した駆動リンクを備えた操舵リンクと、を備え、前２輪が、前記ハンドル軸と一体的に左右方向に回転可能に連結された前記平行リンクによる曲がり角度と、前記ハンドル軸とは前記外歯平歯車と前記内歯とのギア比によって異なる回転角度をする前記操舵リンクによる曲がり角度とを加えた曲がり角度で曲がる三輪自転車により課題解決できた。【選択図】 図６