| 摘要 |
<p>A crank rod used in converting reciprocal movement into rotation, more particularly to an eccentric crank rod for overcoming problems due to failure in conversion of a linearly applied force into a rotation output force at the highest position and the lowest position on a vertical line when the rod is used in converting reciprocal movement into rotation as in a connecting rod of an internal combustion engine or an external combustion engine, or as in a geared crank rod of a bicycle. The crank rod is formed by a biased extension (3), a main lenght portion (5) and an intermediate transition (4) unitarily connecting the biased extension (3) to the main length portion (5). A force-applying portion (6) is formed at an off-centered position nearby an end of the main length portion (5). Both the force-applying portion (6) and the end of the main length portion (5) usually stop at a position across a vertical line L through the center of a crank pin. Both a biased extension (3) and an intermediate transition (4) of the crank rod according to the present invention are formed to have an obtuse internal angle so that an end of the crank rod usually stops after passing over a vertical line regardless of either a weight or a force applied to the force-applying portion (6).</p> |
