| 摘要 |
<p>The system includes two cranks (12) fixed at one end of a connection and rotation pin (6) in a specular position to each other, whereby at the free ends of it, the relative handgrips (10) are connected, lying and rotating on one and the same axis, parallel to the one connecting the cranks and in turn connected by sprocket wheel (5) and a chain (3,4) or a small shaft or a belt or similar to the front wheel of the bicycle. The sprocket wheel that is coaxial with the pin (6) that connects the cranks rotates in idle gear around the pin and has on one side a radially toothed surface that gets engaged with one of two identical toothed surfaces present on the sides of a connection element (7) that is linked to the same rotation of the pin, making the sprocket wheel linked or unlinked to the crank's pin according to the motion of the pin or of the sole connection element.</p> |
