| 摘要 |
<p>The crank wheel for a bicycle carries two rings of teeth (4,5) one ring (4) being larger in dia. than the other ring (5). The two rings can be mounted on radial arms (1) projecting from a boss to which the crank arms (2) are attached. Both rings are mounted on the opposite side of the arms to that from which the boss projects. The wheel is designed for use with a derailleur gear. The arms also carry a ring (8) larger in dia. than the dia. of the larger ring of teeth, mounted on the same side as the boss. This ring can be formed as an integral part of the wheel, attached to the radial arms. The teeth of the smaller ring are in a plane which is offset inwards from the teeth (7) of the larger ring.</p> |
