| 摘要 |
<p>A crank assembly for bicycles and pedal-operated machines comprises a pair of substantially identical cranks (2, 3), each having a substantially tubular hub (4, 5) with a substantially radial lever (6, 7) extending therefrom, and at least one chainring (8, 8') fixed to a drive crank (2) of the pair (2, 3). The cranks (2, 3) are coupled by means of said tubular hubs (4, 5) which are arranged concentrically with a common axis of rotation (R) and with said radial levers (6, 7) extending on opposite sides from said common axis (R). Each of the hubs (4, 5) has a substantially annular connecting portion (17, 18) along a peripheral rim (15, 16), which is uniformly and integrally joined to a respective lever (6, 7). The connecting portion (17) of the drive crank (2) is adapted to fix the one or more chainrings (8, 8'), such that the torque applied to the lever (6, 7) is directly transferred to the one or more chainrings (8, 8') exclusively through the connecting portion (17, 18), thereby reducing torsional stresses and increasing the stiffness of the assembly.</p> |
