摘要 |
<p>The arms (A1-A4) have chain sprockets (B1-B4) at the ends, and are set at 90 degrees to each other. The sprockets are fixed on the ends of the arms, which can rotate on the sprocket shaft (B). The chain (R) can pass over the four driving sprockets and the driven sprocket (A). Two opposed arms have a spring extension mechanism (F1,F2) and there are pedals (P) at the ends of these arms which can rotate with respect to the sprocket wheels.</p> |